---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '21705'
abstract:
- lang: eng
text: "We report the discovery of ATLAS J101342.5−451656.8 (hereafter ATLAS J1013−4516),
an 8.56 minute orbital-period mass-transferring AM Canum Venaticorum (AM CVn)
binary with a mean Gaia magnitude of G = 19.51, identified via periodic variability
in light curves from the Asteroid Terrestrial-impact Last Alert System (ATLAS)
of Gaia white dwarf candidates. Follow-up with the Large Lenslet Array Magellan
Spectrograph shows a helium-dominated accretion disk, and high-speed ULTRACAM
photometry reveals pronounced primary and secondary eclipses. We construct a decade-long
timing baseline leveraging light curves from the ATLAS and Gaia surveys, as well
as the high-speed imagers ULTRACAM on the New Energy Telescope and proto-Lightspeed
on the Magellan Clay telescope. From this timing baseline, we measure an orbital
period derivative of P 1.60 0.07 10 = ± × 12 s s−1. Interpreted in the context
of stable mass transfer, the magnitude and sign of P indicate that the orbital
evolution is governed by the interplay between gravitationalwave-driven angular-momentum
losses and mass transfer, directly probing the donor’s structural response to
mass loss. We constrain the accretor and donor mass based on stable mass-transfer
arguments assuming angularmomentum loss dominated by gravitational-wave emission,
allowing us to infer the characteristic gravitational\r\nwave strain of the binary
for future space-based GW observatories such as the Laser Interferometer Space
Antenna (LISA). We predict a characteristic strain corresponding to a 4 yr LISA
signal-to-noise ratio ≳10, establishing ATLAS J1013−4516 as a strong prospective
LISA source that will probe long-term orbital evolution in the mass-transferring
regime."
acknowledgement: This work has made use of data from the Asteroid Terrestrial-impact
Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System
(ATLAS) project is primarily funded to search for near-Earth asteroids through NASA
grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search
include images and catalogs from the survey area. This work was partially funded
by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889 and STFC grants ST/T000198/1
and ST/S006109/1. The ATLAS science products have been made possible through the
contributions of the University of Hawaii Institute for Astronomy, the Queen’s University
Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory,
and the Millennium Institute of Astrophysics (MAS), Chile. VSD and ULTRACAM are
supported by STFC grant ST/Z000033/1. J.G.M. gratefully acknowledges support from
the Heising-Simons Foundation and the Pappalardo family through the MIT Pappalardo
Fellowship in Physics.
article_number: '237'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Emma T.
full_name: Chickles, Emma T.
last_name: Chickles
- first_name: Joheen
full_name: Chakraborty, Joheen
last_name: Chakraborty
- first_name: Kevin B.
full_name: Burdge, Kevin B.
last_name: Burdge
- first_name: Vik S.
full_name: Dhillon, Vik S.
last_name: Dhillon
- first_name: Paul
full_name: Draghis, Paul
last_name: Draghis
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Matthew J.
full_name: Green, Matthew J.
last_name: Green
- first_name: Aaron
full_name: Householder, Aaron
last_name: Householder
- first_name: Sarah
full_name: Hughes, Sarah
last_name: Hughes
- first_name: Christopher
full_name: Layden, Christopher
last_name: Layden
- first_name: Stuart P.
full_name: Littlefair, Stuart P.
last_name: Littlefair
- first_name: James
full_name: Munday, James
last_name: Munday
- first_name: Ingrid
full_name: Pelisoli, Ingrid
last_name: Pelisoli
- first_name: Maya S.
full_name: Redden, Maya S.
last_name: Redden
- first_name: John
full_name: Tonry, John
last_name: Tonry
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
- first_name: Francesco Elio
full_name: Angile, Francesco Elio
last_name: Angile
- first_name: Alex J.
full_name: Brown, Alex J.
last_name: Brown
- first_name: Noel Castro
full_name: Segura, Noel Castro
last_name: Segura
- first_name: Jack
full_name: Dinsmore, Jack
last_name: Dinsmore
- first_name: Martin
full_name: Dyer, Martin
last_name: Dyer
- first_name: Gabor
full_name: Furesz, Gabor
last_name: Furesz
- first_name: Michelle
full_name: Gabutti, Michelle
last_name: Gabutti
- first_name: James
full_name: Garbutt, James
last_name: Garbutt
- first_name: Juliana
full_name: García-Mejía, Juliana
last_name: García-Mejía
- first_name: Daniel
full_name: Jarvis, Daniel
last_name: Jarvis
- first_name: Mark R.
full_name: Kennedy, Mark R.
last_name: Kennedy
- first_name: Paul
full_name: Kerry, Paul
last_name: Kerry
- first_name: James
full_name: Mccormac, James
last_name: Mccormac
- first_name: Geoffrey
full_name: Mo, Geoffrey
last_name: Mo
- first_name: Dave
full_name: Osip, Dave
last_name: Osip
- first_name: Steven
full_name: Parsons, Steven
last_name: Parsons
- first_name: Eleanor
full_name: Pike, Eleanor
last_name: Pike
- first_name: John J.
full_name: Piotrowski, John J.
last_name: Piotrowski
- first_name: Roger W.
full_name: Romani, Roger W.
last_name: Romani
- first_name: David
full_name: Sahman, David
last_name: Sahman
- first_name: Rob
full_name: Simcoe, Rob
last_name: Simcoe
citation:
ama: Chickles ET, Chakraborty J, Burdge KB, et al. An eclipsing 8.56 minutes orbital
period mass-transferring binary. The Astrophysical Journal. 2026;1000(2).
doi:10.3847/1538-4357/ae4871
apa: Chickles, E. T., Chakraborty, J., Burdge, K. B., Dhillon, V. S., Draghis, P.,
El-Badry, K., … Simcoe, R. (2026). An eclipsing 8.56 minutes orbital period mass-transferring
binary. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae4871
chicago: Chickles, Emma T., Joheen Chakraborty, Kevin B. Burdge, Vik S. Dhillon,
Paul Draghis, Kareem El-Badry, Matthew J. Green, et al. “An Eclipsing 8.56 Minutes
Orbital Period Mass-Transferring Binary.” The Astrophysical Journal. IOP
Publishing, 2026. https://doi.org/10.3847/1538-4357/ae4871.
ieee: E. T. Chickles et al., “An eclipsing 8.56 minutes orbital period mass-transferring
binary,” The Astrophysical Journal, vol. 1000, no. 2. IOP Publishing, 2026.
ista: Chickles ET, Chakraborty J, Burdge KB, Dhillon VS, Draghis P, El-Badry K,
Green MJ, Householder A, Hughes S, Layden C, Littlefair SP, Munday J, Pelisoli
I, Redden MS, Tonry J, van Roestel JC, Angile FE, Brown AJ, Segura NC, Dinsmore
J, Dyer M, Furesz G, Gabutti M, Garbutt J, García-Mejía J, Jarvis D, Kennedy MR,
Kerry P, Mccormac J, Mo G, Osip D, Parsons S, Pike E, Piotrowski JJ, Romani RW,
Sahman D, Simcoe R. 2026. An eclipsing 8.56 minutes orbital period mass-transferring
binary. The Astrophysical Journal. 1000(2), 237.
mla: Chickles, Emma T., et al. “An Eclipsing 8.56 Minutes Orbital Period Mass-Transferring
Binary.” The Astrophysical Journal, vol. 1000, no. 2, 237, IOP Publishing,
2026, doi:10.3847/1538-4357/ae4871.
short: E.T. Chickles, J. Chakraborty, K.B. Burdge, V.S. Dhillon, P. Draghis, K.
El-Badry, M.J. Green, A. Householder, S. Hughes, C. Layden, S.P. Littlefair, J.
Munday, I. Pelisoli, M.S. Redden, J. Tonry, J.C. van Roestel, F.E. Angile, A.J.
Brown, N.C. Segura, J. Dinsmore, M. Dyer, G. Furesz, M. Gabutti, J. Garbutt, J.
García-Mejía, D. Jarvis, M.R. Kennedy, P. Kerry, J. Mccormac, G. Mo, D. Osip,
S. Parsons, E. Pike, J.J. Piotrowski, R.W. Romani, D. Sahman, R. Simcoe, The Astrophysical
Journal 1000 (2026).
date_created: 2026-04-12T22:01:47Z
date_published: 2026-04-01T00:00:00Z
date_updated: 2026-05-04T06:37:12Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/ae4871
external_id:
arxiv:
- '2601.07925'
file:
- access_level: open_access
checksum: c8f64a78f36224d8e0ea1f324e43e389
content_type: application/pdf
creator: dernst
date_created: 2026-05-04T06:36:00Z
date_updated: 2026-05-04T06:36:00Z
file_id: '21782'
file_name: 2026_AstrophysicalJournal_Chickles.pdf
file_size: 1225916
relation: main_file
success: 1
file_date_updated: 2026-05-04T06:36:00Z
has_accepted_license: '1'
intvolume: ' 1000'
issue: '2'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: An eclipsing 8.56 minutes orbital period mass-transferring binary
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1000
year: '2026'
...
---
OA_place: publisher
OA_type: gold
_id: '21710'
abstract:
- lang: eng
text: "Early results from JWST suggest that Epoch of Reionization (EoR) galaxies
produce copious ionizing photons, which, if they escape efficiently, could cause
reionization to occur too early. We study this problem using JWST imaging and
prism spectroscopy for 412 galaxies at 4.5 < z < 9.0. We fit these data simultaneously
with stellar population and nebular emission models that include a parameter for
the fraction of ionizing photons that escape the galaxy, fesc. We find that the
ionization production efficiency, ξion = Q(H0)/LUV, increases with redshift and
decreasing UV luminosity, but shows significant scatter, (log ion z, MUV) 0.3
dex. The inferred escape fractions averaged over the population are low, ranging
from〈fesc〉 ≃ 2.6% ± 1.4% at 6 < z < 9 to 6.5% ± 2.2% at 4.5 < z < 6, with weak
or no indication of evolution with redshift. This implies that in our models most
of the ionizing photons need to be absorbed to account for the nebular emission.
We compute the impact of our results on reionization, including the distributions
for ξion and fesc, and the evolution and uncertainty of the UV luminosity function.
Considering galaxies brighter than MUV < −16 mag would produce an intergalactic
medium hydrogen-ionized fraction of xe = 0.5 at 5.3 < z < 5.8, possibly too late
compared to constraints from from quasistellar\r\nobject (QSO) sight lines. Including
fainter galaxies, MUV < −14 mag, we obtain xe = 0.5 at 6.0 < z < 8.1, fully consistent
with QSO and cosmic microwave background data. This implies that EoR galaxies
produce plenty of ionizing photons, but that these do not efficiently escape.
This may be a result of high gas column densities combined with burstier star
formation histories, which limit the time massive stars are able to clear channels
through the gas for ionizing photons to escape."
acknowledgement: "We wish to thank our colleagues in the CEERS collaboration for their
hard work and valuable contributions on this project. We extend our sincerest thanks
to the anonymous referee whose critical and constructive report improved the quality
of this manuscript. We also thank the JADES team for providing an excellent dataset
for science. We with to thank colleagues for valuable discussions, feedback, and
suggestions, including John Chisholm, Kevin Huffenberger, Jessica\r\nMeh, Julian
Muñoz, Irene Shivaei, Justin Spilker, Aaron Smith, and Romain Teyssier.\r\nPortions
of this research were conducted with the advanced computing resources provided by
Texas A&M High Performance Research Computing (HPRC, http://hprc.tamu.edu). This
work benefited from support from the George P. and Cynthia Woods Mitchell Institute
for Fundamental Physics and Astronomy at Texas A&M University. CP thanks Marsha
and Ralph Schilling for generous support of this research. This work was partially
support by the Future Investigators in NASA Earth and Space Science and Technology
(FINESST) program grant No. 80NSSC23K1487. R.A. acknowledges support of grant PID2023-147386NB-I00
funded by MICIU/AEI/10.13039/501100011033 and by ERDF/EU, and the Severo Ochoa grant
CEX2021-001131-S funded by MCIN/AEI/10.13039/50110001103. A.C.C. acknowledges support
from a UKRI Frontier Research Guarantee Grant (PI Carnall; grant reference EP/Y037065/1)
This work acknowledges support from the NASA/ESA/CSA James Webb Space Telescope
through the\r\nSpace Telescope Science Institute, which is operated by the Association
of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-03127.
Support for program JWST-ERS-01345.009-A, JWST-GO-02079.013-A, JWST-GO-06368.011-A,
and JWST-GO-01837.030-A, was provided by NASA through a grant from the Space Telescope
Science Institute, which is operated by the Association of Universities for Research
in Astronomy, Inc., under NASA contract NAS 5-03127. This work made use of v2.2
of the Binary Population\r\nand Spectral Synthesis (BPASS) models as described in
E. R. Stanway & J. J. Eldridge (2018)."
article_number: '111'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Casey
full_name: Papovich, Casey
last_name: Papovich
- first_name: Justin W.
full_name: Cole, Justin W.
last_name: Cole
- first_name: Weida
full_name: Hu, Weida
last_name: Hu
- first_name: Steven L.
full_name: Finkelstein, Steven L.
last_name: Finkelstein
- first_name: Lu
full_name: Shen, Lu
last_name: Shen
- first_name: Pablo
full_name: Arrabal Haro, Pablo
last_name: Arrabal Haro
- first_name: Ricardo O.
full_name: Amorín, Ricardo O.
last_name: Amorín
- first_name: Bren E.
full_name: Backhaus, Bren E.
last_name: Backhaus
- first_name: Micaela B.
full_name: Bagley, Micaela B.
last_name: Bagley
- first_name: Rachana
full_name: Bhatawdekar, Rachana
last_name: Bhatawdekar
- first_name: Antonello
full_name: Calabrò, Antonello
last_name: Calabrò
- first_name: Adam C.
full_name: Carnall, Adam C.
last_name: Carnall
- first_name: Nikko J.
full_name: Cleri, Nikko J.
last_name: Cleri
- first_name: Emanuele
full_name: Daddi, Emanuele
last_name: Daddi
- first_name: Mark
full_name: Dickinson, Mark
last_name: Dickinson
- first_name: Norman A.
full_name: Grogin, Norman A.
last_name: Grogin
- first_name: Benne W.
full_name: Holwerda, Benne W.
last_name: Holwerda
- first_name: Anne E.
full_name: Jaskot, Anne E.
last_name: Jaskot
- first_name: Anton M.
full_name: Koekemoer, Anton M.
last_name: Koekemoer
- first_name: Mario
full_name: Llerena, Mario
last_name: Llerena
- first_name: Ray A.
full_name: Lucas, Ray A.
last_name: Lucas
- first_name: Sara
full_name: Mascia, Sara
id: edaf889c-c7cd-11ef-ab1b-bb28c431bd29
last_name: Mascia
- first_name: Fabio
full_name: Pacucci, Fabio
last_name: Pacucci
- first_name: Laura
full_name: Pentericci, Laura
last_name: Pentericci
- first_name: Pablo G.
full_name: Pérez-González, Pablo G.
last_name: Pérez-González
- first_name: Nor
full_name: Pirzkal, Nor
last_name: Pirzkal
- first_name: Srinivasan
full_name: Raghunathan, Srinivasan
last_name: Raghunathan
- first_name: Lise Marie
full_name: Seillé, Lise Marie
last_name: Seillé
- first_name: Rachel S.
full_name: Somerville, Rachel S.
last_name: Somerville
- first_name: L. Y.Aaron
full_name: Yung, L. Y.Aaron
last_name: Yung
citation:
ama: Papovich C, Cole JW, Hu W, et al. Galaxies in the epoch of reionization are
all bark and no bite-plenty of ionizing photons, low escape fractions. The
Astrophysical Journal. 2026;1000(1). doi:10.3847/1538-4357/ae3b25
apa: Papovich, C., Cole, J. W., Hu, W., Finkelstein, S. L., Shen, L., Arrabal Haro,
P., … Yung, L. Y. A. (2026). Galaxies in the epoch of reionization are all bark
and no bite-plenty of ionizing photons, low escape fractions. The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae3b25
chicago: Papovich, Casey, Justin W. Cole, Weida Hu, Steven L. Finkelstein, Lu Shen,
Pablo Arrabal Haro, Ricardo O. Amorín, et al. “Galaxies in the Epoch of Reionization
Are All Bark and No Bite-Plenty of Ionizing Photons, Low Escape Fractions.” The
Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae3b25.
ieee: C. Papovich et al., “Galaxies in the epoch of reionization are all
bark and no bite-plenty of ionizing photons, low escape fractions,” The Astrophysical
Journal, vol. 1000, no. 1. IOP Publishing, 2026.
ista: Papovich C, Cole JW, Hu W, Finkelstein SL, Shen L, Arrabal Haro P, Amorín
RO, Backhaus BE, Bagley MB, Bhatawdekar R, Calabrò A, Carnall AC, Cleri NJ, Daddi
E, Dickinson M, Grogin NA, Holwerda BW, Jaskot AE, Koekemoer AM, Llerena M, Lucas
RA, Mascia S, Pacucci F, Pentericci L, Pérez-González PG, Pirzkal N, Raghunathan
S, Seillé LM, Somerville RS, Yung LYA. 2026. Galaxies in the epoch of reionization
are all bark and no bite-plenty of ionizing photons, low escape fractions. The
Astrophysical Journal. 1000(1), 111.
mla: Papovich, Casey, et al. “Galaxies in the Epoch of Reionization Are All Bark
and No Bite-Plenty of Ionizing Photons, Low Escape Fractions.” The Astrophysical
Journal, vol. 1000, no. 1, 111, IOP Publishing, 2026, doi:10.3847/1538-4357/ae3b25.
short: C. Papovich, J.W. Cole, W. Hu, S.L. Finkelstein, L. Shen, P. Arrabal Haro,
R.O. Amorín, B.E. Backhaus, M.B. Bagley, R. Bhatawdekar, A. Calabrò, A.C. Carnall,
N.J. Cleri, E. Daddi, M. Dickinson, N.A. Grogin, B.W. Holwerda, A.E. Jaskot, A.M.
Koekemoer, M. Llerena, R.A. Lucas, S. Mascia, F. Pacucci, L. Pentericci, P.G.
Pérez-González, N. Pirzkal, S. Raghunathan, L.M. Seillé, R.S. Somerville, L.Y.A.
Yung, The Astrophysical Journal 1000 (2026).
date_created: 2026-04-12T22:01:49Z
date_published: 2026-03-20T00:00:00Z
date_updated: 2026-05-04T10:44:57Z
day: '20'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae3b25
external_id:
arxiv:
- '2505.08870'
file:
- access_level: open_access
checksum: 0031a6f197a3fa8c2845de10b6bdc696
content_type: application/pdf
creator: dernst
date_created: 2026-05-04T10:40:07Z
date_updated: 2026-05-04T10:40:07Z
file_id: '21791'
file_name: 2026_AstrophysicalJour_Papovich.pdf
file_size: 6670398
relation: main_file
success: 1
file_date_updated: 2026-05-04T10:40:07Z
has_accepted_license: '1'
intvolume: ' 1000'
issue: '1'
language:
- iso: eng
month: '03'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Galaxies in the epoch of reionization are all bark and no bite-plenty of ionizing
photons, low escape fractions
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1000
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '21712'
abstract:
- lang: eng
text: Supermassive black hole binary (SMBHB) systems are expected to form as a consequence
of galaxy mergers. At subparsec separations, SMBHBs can be identified as quasars
with periodic variability, with previous periodicity searches uncovering significant
candidates. However, these searches focused primarily on sinusoidal signals, while
theoretical models and hydrodynamical simulations predict that binaries produce
more complex non-sinusoidal pulse shapes. Here we examine the efficacy of the
Lomb–Scargle periodogram (LSP; one of the most popular tools for periodicity searches
in unevenly sampled lightcurves) to detect periodicities with a sawtooth shape
mimicking results of hydrodynamical simulations. We simulate idealized well-sampled
lightcurves, lightcurves that mimic the data in the Palomar Transient Factory
(PTF) analyzed in M. Charisi et al. (2016), and lightcurves that resemble our
expectations for single-band data in the upcoming Legacy Survey of Space and Time
(LSST) of the Rubin Observatory. We approximate quasar variability with a damped
random walk (DRW) model, inject sinusoidal and sawtooth pulse shapes, and assess
their statistical significance. We find that in the presence of red noise, the
LSP detects a relatively low fraction of the sinusoidal signals (∼45%, ∼24%, and
∼23%, in the PTF-like, idealized, and LSST-like lightcurves, respectively). The
fraction is significantly reduced for sawtooth periodicity (with only ∼9% in PTF-like
and ∼1% in idealized and LSST-like lightcurves). These low recovery rates imply
that previous searches have missed the large majority of binaries. They also have
significant implications for the detection of SMBHBs in upcoming LSST necessitating
the development of advanced tools that go beyond the simple LSP.
acknowledgement: M.C. acknowledges support by the European Union (ERC; MMMonsters,
101117624). This work was also supported in part by NASA grants 80NSSC24K0440 and
80NSSC22K0822. This research used the resources of the Center for Institutional
Research Computing at Washington State University.
article_number: '316'
article_processing_charge: Yes
article_type: original
author:
- first_name: Allison
full_name: Lin, Allison
last_name: Lin
- first_name: Maria
full_name: Charisi, Maria
last_name: Charisi
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
orcid: 0000-0003-3633-5403
citation:
ama: Lin A, Charisi M, Haiman Z. Lomb-scargle periodogram struggles with non-sinusoidal
supermassive Black Hole binary signatures in quasar lightcurves. The Astrophysical
Journal. 2026;997(2). doi:10.3847/1538-4357/ae29a7
apa: Lin, A., Charisi, M., & Haiman, Z. (2026). Lomb-scargle periodogram struggles
with non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves.
The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae29a7
chicago: Lin, Allison, Maria Charisi, and Zoltán Haiman. “Lomb-Scargle Periodogram
Struggles with Non-Sinusoidal Supermassive Black Hole Binary Signatures in Quasar
Lightcurves.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae29a7.
ieee: A. Lin, M. Charisi, and Z. Haiman, “Lomb-scargle periodogram struggles with
non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves,”
The Astrophysical Journal, vol. 997, no. 2. IOP Publishing, 2026.
ista: Lin A, Charisi M, Haiman Z. 2026. Lomb-scargle periodogram struggles with
non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves.
The Astrophysical Journal. 997(2), 316.
mla: Lin, Allison, et al. “Lomb-Scargle Periodogram Struggles with Non-Sinusoidal
Supermassive Black Hole Binary Signatures in Quasar Lightcurves.” The Astrophysical
Journal, vol. 997, no. 2, 316, IOP Publishing, 2026, doi:10.3847/1538-4357/ae29a7.
short: A. Lin, M. Charisi, Z. Haiman, The Astrophysical Journal 997 (2026).
date_created: 2026-04-12T22:01:49Z
date_published: 2026-02-01T00:00:00Z
date_updated: 2026-05-04T10:26:59Z
day: '01'
ddc:
- '520'
department:
- _id: ZoHa
doi: 10.3847/1538-4357/ae29a7
file:
- access_level: open_access
checksum: 5162d1539ef7d10927ef73d8b4500017
content_type: application/pdf
creator: dernst
date_created: 2026-05-04T10:24:49Z
date_updated: 2026-05-04T10:24:49Z
file_id: '21789'
file_name: 2026_AstrophysicalJour_Lin.pdf
file_size: 2619679
relation: main_file
success: 1
file_date_updated: 2026-05-04T10:24:49Z
has_accepted_license: '1'
intvolume: ' 997'
issue: '2'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Lomb-scargle periodogram struggles with non-sinusoidal supermassive Black Hole
binary signatures in quasar lightcurves
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 997
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21715'
abstract:
- lang: eng
text: New populations of red active galactic nuclei (known as “little red dots”)
discovered by JWST exhibit remarkable spectral energy distributions. Leveraging
X-ray through far-infrared observations of two of the most luminous known little
red dots, we directly measure their bolometric luminosities. We find evidence
that more than half of the bolometric luminosity likely emerges in the rest-frame
optical, with Lbol/L5100 = 5, roughly half the value for “standard” active galactic
nuclei. Meanwhile, the X-ray emitting corona, UV-emitting blackbody, and reprocessed
mid to far-infrared emission are all considerably subdominant, assuming that the
far-infrared luminosity is well below current measured limits. We present new
bolometric corrections that dramatically lower inferred bolometric luminosities
by a factor of 10 compared to published values in the literature. These bolometric
corrections are in accord with expectations from models in which gas absorption
and reprocessing are responsible for the red rest-frame optical colors of little
red dots. We discuss how this lowered luminosity scale suggests a lower mass scale
for the population by at least an order of magnitude (e.g., ∼105–107 M⊙ black
holes, and ∼108 M⊙ galaxies), alleviating tensions with clustering, overmassive
black holes, and the integrated black hole mass density in the Universe.
acknowledgement: "We benefit from the following JWST programs: UNCOVER (JWST/GO #2561;
Labbé & Bezanson); ALT (JWST-GO #3516; Naidu & Matthee); MegaScience (JWST-GO #4111;
Suess); RUBIES (JWST-GO #4233; de Graaff & Brammer); PRIMER (JWST/GO #1837; Dunlop).\r\n\r\nWe
acknowledge funding from NSF/AAG #2306950, JWST-GO-02561, JWST-GO-03516, and JWST-GO-04111,
provided through a grant from the STScI under NASA contract NAS5-03127. I.L. acknowledges
support from Australian Research Council Future Fellowship FT220100798. K.G. and
T.N. acknowledge support from Australian Research Council Laureate Fellowship FL180100060.
A.Z. acknowledges support by grant No. 2020750 from the United States-Israel Binational
Science Foundation (BSF) and grant No. 2109066 from the United States National Science
Foundation (NSF); by the Ministry of Science & Technology, Israel; and by the Israel
Science Foundation grant No. 864/23. J.M. and I.K. are funded by the European Union
(ERC, AGENTS, 101076224). Views and opinions expressed are, however, those of the
author(s) only and do not necessarily reflect those of the European Union or the
European Research Council. Neither the European Union nor the granting authority
can be held responsible for them. Y.F. acknowledges support from JSPS KAKENHI grant
No. JSPS KAKENHI grant Nos. JP22K21349 and JP23K13149. This work has received funding
from the Swiss State Secretariat for Education, Research and Innovation (SERI) under
contract No. MB22.00072, as well as from the Swiss National Science Foundation (SNSF)
through project grant 200020_207349. The Cosmic Dawn Center (DAWN) is funded by
the Danish National Research Foundation under grant DNRF140. Support for this work
for RPN was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51515.001-A
awarded by the Space Telescope Science Institute, which is operated by the Association
of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.
The work of CCW is supported by NOIRLab, which is managed by the Association of
Universities for Research in Astronomy (AURA) under a cooperative agreement with
the National Science Foundation. J.M. acknowledges funding by the European Union
(ERC, AGENTS, 101076224). R.E.H. acknowledges support by the German Aerospace Center
(DLR) and the Federal Ministry for Economic Affairs and Energy (BMWi) through program
50OR2403 “RUBIES.”"
article_number: '129'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: David J.
full_name: Setton, David J.
last_name: Setton
- first_name: Lukas J.
full_name: Furtak, Lukas J.
last_name: Furtak
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: Marta
full_name: Volonteri, Marta
last_name: Volonteri
- first_name: Pratika
full_name: Dayal, Pratika
last_name: Dayal
- first_name: Ivo
full_name: Labbe, Ivo
last_name: Labbe
- first_name: Pieter
full_name: Van Dokkum, Pieter
last_name: Van Dokkum
- first_name: Rachel
full_name: Bezanson, Rachel
last_name: Bezanson
- first_name: Gabriel
full_name: Brammer, Gabriel
last_name: Brammer
- first_name: Sam E.
full_name: Cutler, Sam E.
last_name: Cutler
- first_name: Karl
full_name: Glazebrook, Karl
last_name: Glazebrook
- first_name: Anna
full_name: De Graaff, Anna
last_name: De Graaff
- first_name: Michaela
full_name: Hirschmann, Michaela
last_name: Hirschmann
- first_name: Raphael E.
full_name: Hviding, Raphael E.
last_name: Hviding
- first_name: Vasily
full_name: Kokorev, Vasily
last_name: Kokorev
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Hanpu
full_name: Liu, Hanpu
last_name: Liu
- first_name: Yilun
full_name: Ma, Yilun
last_name: Ma
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Themiya
full_name: Nanayakkara, Themiya
last_name: Nanayakkara
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Richard
full_name: Pan, Richard
last_name: Pan
- first_name: Sedona H.
full_name: Price, Sedona H.
last_name: Price
- first_name: Justin S.
full_name: Spilker, Justin S.
last_name: Spilker
- first_name: Bingjie
full_name: Wang, Bingjie
last_name: Wang
- first_name: John R.
full_name: Weaver, John R.
last_name: Weaver
- first_name: Katherine E.
full_name: Whitaker, Katherine E.
last_name: Whitaker
- first_name: Christina C.
full_name: Williams, Christina C.
last_name: Williams
- first_name: Adi
full_name: Zitrin, Adi
last_name: Zitrin
citation:
ama: 'Greene JE, Setton DJ, Furtak LJ, et al. What you see is what you get: Empirically
measured bolometric luminosities of Little Red Dots. The Astrophysical Journal.
2026;996(2). doi:10.3847/1538-4357/ae1836'
apa: 'Greene, J. E., Setton, D. J., Furtak, L. J., Naidu, R. P., Volonteri, M.,
Dayal, P., … Zitrin, A. (2026). What you see is what you get: Empirically measured
bolometric luminosities of Little Red Dots. The Astrophysical Journal.
IOP Publishing. https://doi.org/10.3847/1538-4357/ae1836'
chicago: 'Greene, Jenny E., David J. Setton, Lukas J. Furtak, Rohan P. Naidu, Marta
Volonteri, Pratika Dayal, Ivo Labbe, et al. “What You See Is What You Get: Empirically
Measured Bolometric Luminosities of Little Red Dots.” The Astrophysical Journal.
IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae1836.'
ieee: 'J. E. Greene et al., “What you see is what you get: Empirically measured
bolometric luminosities of Little Red Dots,” The Astrophysical Journal,
vol. 996, no. 2. IOP Publishing, 2026.'
ista: 'Greene JE, Setton DJ, Furtak LJ, Naidu RP, Volonteri M, Dayal P, Labbe I,
Van Dokkum P, Bezanson R, Brammer G, Cutler SE, Glazebrook K, De Graaff A, Hirschmann
M, Hviding RE, Kokorev V, Leja J, Liu H, Ma Y, Matthee JJ, Nanayakkara T, Oesch
PA, Pan R, Price SH, Spilker JS, Wang B, Weaver JR, Whitaker KE, Williams CC,
Zitrin A. 2026. What you see is what you get: Empirically measured bolometric
luminosities of Little Red Dots. The Astrophysical Journal. 996(2), 129.'
mla: 'Greene, Jenny E., et al. “What You See Is What You Get: Empirically Measured
Bolometric Luminosities of Little Red Dots.” The Astrophysical Journal,
vol. 996, no. 2, 129, IOP Publishing, 2026, doi:10.3847/1538-4357/ae1836.'
short: J.E. Greene, D.J. Setton, L.J. Furtak, R.P. Naidu, M. Volonteri, P. Dayal,
I. Labbe, P. Van Dokkum, R. Bezanson, G. Brammer, S.E. Cutler, K. Glazebrook,
A. De Graaff, M. Hirschmann, R.E. Hviding, V. Kokorev, J. Leja, H. Liu, Y. Ma,
J.J. Matthee, T. Nanayakkara, P.A. Oesch, R. Pan, S.H. Price, J.S. Spilker, B.
Wang, J.R. Weaver, K.E. Whitaker, C.C. Williams, A. Zitrin, The Astrophysical
Journal 996 (2026).
date_created: 2026-04-12T22:01:50Z
date_published: 2026-01-10T00:00:00Z
date_updated: 2026-05-04T11:20:42Z
day: '10'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae1836
external_id:
arxiv:
- '2509.05434'
file:
- access_level: open_access
checksum: 7b3cb025d4bcaa35c6e52bd0c8fb6cf4
content_type: application/pdf
creator: dernst
date_created: 2026-05-04T11:19:48Z
date_updated: 2026-05-04T11:19:48Z
file_id: '21792'
file_name: 2026_AstrophysicalJour_Greene.pdf
file_size: 684400
relation: main_file
success: 1
file_date_updated: 2026-05-04T11:19:48Z
has_accepted_license: '1'
intvolume: ' 996'
issue: '2'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
project:
- _id: bd9b2118-d553-11ed-ba76-db24564edfea
grant_number: '101076224'
name: Young galaxies as tracers and agents of cosmic reionization
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'What you see is what you get: Empirically measured bolometric luminosities
of Little Red Dots'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 996
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21725'
abstract:
- lang: eng
text: "The initial–final mass relation (IFMR) links a star’s birth mass to the mass
of its white dwarf (WD) remnant, providing key constraints on stellar evolution.
Open clusters offer the most straightforward way to empirically determine the
IFMR, as their well-defined ages allow for direct progenitor lifetime estimates.
We construct the most comprehensive open cluster WD IFMR to date by combining
new spectroscopy of 22 WDs with an extensive literature review of WDs with strong
cluster associations. To minimize systematics, we restrict our analysis to spectroscopically
confirmed hydrogen-atmosphere (DA) WDs consistent with single-stellar origins.
We separately analyze a subset with reliable Gaia-based astrometric membership
assessments, as well as a full sample that adds WDs with strong cluster associations
whose membership cannot be reliably assessed with Gaia. The Gaia-based sample
includes 69 spectroscopically confirmed DA WDs, more than doubling the sample
size of previous Gaia-based open cluster IFMRs. The full sample, which includes
53 additional literature WDs,\r\nincreases the total number of cluster WDs by
over 50% relative to earlier works. We provide functional forms for both the Gaia-based
and full-sample IFMRs. The Gaia-based result useful for Mi � 2.67 M⊙ is Mf = [0.179
0.100H (Mi 3.84 M )] × (Mi 3.84 M ) + 0.628 M , where H(x) is the Heaviside step
function. Comparing our IFMR to recent literature, we identify significant deviations
from best-fit IFMRs derived from both Gaia-based volume-limited samples of field
WDs and double WD binaries, with the largest discrepancy occurring for initial
masses of about 5 M⊙."
acknowledgement: "The authors would like to thank the anonymous referee for their
constructive feedback, which helped improve the clarify of the manuscript. This
work was supported in part by the Natural Sciences and Engineering Research Council
of Canada Discovery grants Nos. DG-RGPIN-2022-03051 and DG-RGPIN-2023-04486. This
research received funding from the European Research Council under the European
Union’s Horizon 2020 research and innovation program number 101002408 (MOS100PC).
This work includes results based on observations obtained at the international Gemini
Observatory, a program of NSF’s NOIRLab, which is managed by the Association of
Universities for Research in Astronomy (AURA) under a cooperative agreement with
the National Science Foundation on behalf of the Gemini Observatory partnership:
the National Science Foundation (United States), National Research Council (Canada),
Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología
e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações
(Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). This
work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia),
processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).
Funding for the DPAC has been provided by national institutions, in particular the
institutions participating in the Gaia Multilateral Agreement. Some of the data
presented herein were obtained at the W. M. Keck Observatory, which is operated
as a scientific partnership among the California Institute of Technology, the University
of California, and the National Aeronautics and Space Administration. The Observatory
was made possible by the generous financial support of the W. M. Keck Foundation.
Gemini spectra were processed using the DRAGONS package (K. Labrie et al. 2023).
LRIS spectra were reduced using the Lpipe pipeline (D. A. Perley 2019).\r\n\r\nFacilities:
Gaia - (DR2 & DR3), Gemini:Gillett - Gillett Gemini North Telescope (GMOS-N), Gemini:South
- Gemini South Telescope (GMOS-S), Keck:I - KECK I Telescope (LRIS).\r\n\r\nSoftware:
Astropy (Astropy Collaboration et al. 2013,2018, 2022), emcee (D. Foreman-Mackey
et al. 2013)."
article_number: '69'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: David R.
full_name: Miller, David R.
last_name: Miller
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Jeremy
full_name: Heyl, Jeremy
last_name: Heyl
- first_name: Harvey B.
full_name: Richer, Harvey B.
last_name: Richer
- first_name: Mark A.
full_name: Hollands, Mark A.
last_name: Hollands
- first_name: Pier Emmanuel
full_name: Tremblay, Pier Emmanuel
last_name: Tremblay
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
citation:
ama: Miller DR, Caiazzo I, Heyl J, et al. The White Dwarf initial–final mass relation
from open clusters in Gaia DR3. The Astrophysical Journal. 2026;996(1).
doi:10.3847/1538-4357/ae18c8
apa: Miller, D. R., Caiazzo, I., Heyl, J., Richer, H. B., Hollands, M. A., Tremblay,
P. E., … Vanderbosch, Z. P. (2026). The White Dwarf initial–final mass relation
from open clusters in Gaia DR3. The Astrophysical Journal. IOP Publishing.
https://doi.org/10.3847/1538-4357/ae18c8
chicago: Miller, David R., Ilaria Caiazzo, Jeremy Heyl, Harvey B. Richer, Mark A.
Hollands, Pier Emmanuel Tremblay, Kareem El-Badry, Antonio C. Rodriguez, and Zachary
P. Vanderbosch. “The White Dwarf Initial–Final Mass Relation from Open Clusters
in Gaia DR3.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae18c8.
ieee: D. R. Miller et al., “The White Dwarf initial–final mass relation from
open clusters in Gaia DR3,” The Astrophysical Journal, vol. 996, no. 1.
IOP Publishing, 2026.
ista: Miller DR, Caiazzo I, Heyl J, Richer HB, Hollands MA, Tremblay PE, El-Badry
K, Rodriguez AC, Vanderbosch ZP. 2026. The White Dwarf initial–final mass relation
from open clusters in Gaia DR3. The Astrophysical Journal. 996(1), 69.
mla: Miller, David R., et al. “The White Dwarf Initial–Final Mass Relation from
Open Clusters in Gaia DR3.” The Astrophysical Journal, vol. 996, no. 1,
69, IOP Publishing, 2026, doi:10.3847/1538-4357/ae18c8.
short: D.R. Miller, I. Caiazzo, J. Heyl, H.B. Richer, M.A. Hollands, P.E. Tremblay,
K. El-Badry, A.C. Rodriguez, Z.P. Vanderbosch, The Astrophysical Journal 996 (2026).
date_created: 2026-04-12T22:01:52Z
date_published: 2026-01-01T00:00:00Z
date_updated: 2026-04-13T08:39:39Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/ae18c8
external_id:
arxiv:
- '2510.24877'
file:
- access_level: open_access
checksum: 65a8237a519188af83b6dc4d47ad85fa
content_type: application/pdf
creator: dernst
date_created: 2026-04-13T08:36:50Z
date_updated: 2026-04-13T08:36:50Z
file_id: '21733'
file_name: 2026_AstrophysicalJournal_Miller.pdf
file_size: 19310053
relation: main_file
success: 1
file_date_updated: 2026-04-13T08:36:50Z
has_accepted_license: '1'
intvolume: ' 996'
issue: '1'
keyword:
- White dwarf stars
- Open star clusters
- Compact objects
- Stellar evolution
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: The White Dwarf initial–final mass relation from open clusters in Gaia DR3
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 996
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21760'
abstract:
- lang: eng
text: 3I/ATLAS is the third interstellar object discovered to date, following 1I/‘Oumuamua
and 2I/Borisov. Its unusually high excess velocity and active cometary nature
make it a key probe of the Galactic population of icy planetesimals. Understanding
its origin requires its past trajectory through the Galaxy to be traced and the
possible role of stellar encounters to be assessed, both as a potential origin
and a perturber to its orbit. We integrated the orbit of 3I/ATLAS backward in
time for 10 Myr, together with a sample of Gaia DR3 stars with high-quality astrometry
and radial velocities, to identify close passages within 2 pc. We identify 93
nominal encounters, 62 of which are significant at the 2σ level. However, none
of these encounters produced any meaningful perturbation. The strongest perturber
Gaia DR3 6863591389529611264 at 0.30 pc and with a relative velocity of 35 km
s−1, imparted only a velocity change of ∣Δv∣ ≃ 5 × 10−4 km s−1 to the orbit
of 3I/ATLAS. Our results indicate that no stellar flybys within the past 10 Myr
and 500 pc contained in Gaia DR3 can account for the present trajectory of 3I/ATLAS
or be associated with its origin. We further show that 3I/ATLAS is kinematically
consistent with a thin-disk population, despite its large peculiar velocity.
acknowledgement: We thank the anonymous referee for a careful reading of the manuscript
and for constructive comments that improved the paper. X.P.C. and S.T. thank J.L.
Gragera-Más and Ylva Götberg for their valuable feedback and comments. X.P.C. acknowledges
financial support from the Spanish National Programme for the Promotion of Talent
and its Employability grant PRE2022-104959 cofunded by the European Social Fund.
S.T. acknowledges the funding from the European Union’s Horizon 2020 research and
innovation program under the Marie Skłodowska-Curie grant agreement No. 101034413.
E.V. acknowledges support from the DISCOBOLO project funded by the Spanish Ministerio
de Ciencia, Innovación y Universidades under grant PID2021-127289NB-I00. A.J.M.
acknowledges support from the Swedish National Space Agency (Career grant 2023-00146).
X.P.C. and M.M. acknowledge support from the Spanish Ministerio de Ciencia, Innovaciòn
y Universidades under grants PID2021122842OB-C22 and PID2024-157964OB-C22; from
the Xunta de Galicia and the European Union (FEDER Galicia 2021-2027 Program) Ref.
ED431B 2024/21, ED431B 2024/02, and CITIC ED431G 2023/01. This work has made use
of data from the European Space Agency (ESA) Gaia mission and processed by the Gaia
Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided
by national institutions, particularly the institutions participating in the Gaia
Multilateral Agreement.
article_number: '146'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: X.
full_name: Pérez-Couto, X.
last_name: Pérez-Couto
- first_name: Santiago
full_name: Torres Rodriguez, Santiago
id: a8df4360-4328-11ee-8f1a-e502d0c83fc2
last_name: Torres Rodriguez
orcid: 0000-0002-3150-8988
- first_name: E.
full_name: Villaver, E.
last_name: Villaver
- first_name: A. J.
full_name: Mustill, A. J.
last_name: Mustill
- first_name: M.
full_name: Manteiga, M.
last_name: Manteiga
citation:
ama: 'Pérez-Couto X, Torres Rodriguez S, Villaver E, Mustill AJ, Manteiga M. 3I/ATLAS:
In search of the witnesses to its voyage. The Astrophysical Journal. 2026;1001(2).
doi:10.3847/1538-4357/ae56ff'
apa: 'Pérez-Couto, X., Torres Rodriguez, S., Villaver, E., Mustill, A. J., &
Manteiga, M. (2026). 3I/ATLAS: In search of the witnesses to its voyage. The
Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae56ff'
chicago: 'Pérez-Couto, X., Santiago Torres Rodriguez, E. Villaver, A. J. Mustill,
and M. Manteiga. “3I/ATLAS: In Search of the Witnesses to Its Voyage.” The
Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae56ff.'
ieee: 'X. Pérez-Couto, S. Torres Rodriguez, E. Villaver, A. J. Mustill, and M. Manteiga,
“3I/ATLAS: In search of the witnesses to its voyage,” The Astrophysical Journal,
vol. 1001, no. 2. IOP Publishing, 2026.'
ista: 'Pérez-Couto X, Torres Rodriguez S, Villaver E, Mustill AJ, Manteiga M. 2026.
3I/ATLAS: In search of the witnesses to its voyage. The Astrophysical Journal.
1001(2), 146.'
mla: 'Pérez-Couto, X., et al. “3I/ATLAS: In Search of the Witnesses to Its Voyage.”
The Astrophysical Journal, vol. 1001, no. 2, 146, IOP Publishing, 2026,
doi:10.3847/1538-4357/ae56ff.'
short: X. Pérez-Couto, S. Torres Rodriguez, E. Villaver, A.J. Mustill, M. Manteiga,
The Astrophysical Journal 1001 (2026).
date_created: 2026-04-26T22:01:46Z
date_published: 2026-04-20T00:00:00Z
date_updated: 2026-04-28T13:08:39Z
day: '20'
ddc:
- '520'
department:
- _id: LiBu
doi: 10.3847/1538-4357/ae56ff
ec_funded: 1
external_id:
arxiv:
- '2509.07678'
file:
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checksum: c3daf49261a9933c079854c38eec316f
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creator: dernst
date_created: 2026-04-28T13:06:00Z
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month: '04'
oa: 1
oa_version: Published Version
project:
- _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c
call_identifier: H2020
grant_number: '101034413'
name: 'IST-BRIDGE: International postdoctoral program'
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: '3I/ATLAS: In search of the witnesses to its voyage'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1001
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21844'
abstract:
- lang: eng
text: Little red dots (LRDs) are a newly identified class of broad-line active galactic
nuclei (AGNs) with a distinctive V-shaped spectrum characterized by red optical
and blue UV continuum emission. Their high abundance at redshifts of z ∼ 6–8 and
decline at lower redshifts suggest a transient origin. We propose that the spectral
shape of LRDs originates from compact binary black hole systems, in which each
black hole is surrounded by a mini-disk and embedded within a larger circumbinary
disk. With a binary separation of ≲103 Schwarzschild radii, the Wien tail of a
T ≃ 5000 K blackbody spectrum at the inner edge of the circumbinary disk produces
the red optical emission, while the mini-disks power the UV continuum. Binary
torques carve out a gap between the circumbinary disk and the mini-disks, setting
the turnover wavelength of the V-shaped spectrum around the Balmer limit. This
scenario naturally reproduces LRD spectra requiring only modest dust attenuation
(AV ≲ 1 mag), resolving overestimated luminosities for LRDs in previous studies
and alleviating a tension with the so-called Sołtan argument. This model predicts
distinct spectral evolution as the binary orbit decays through binary disk interactions
and gravitational-wave (GW) emission, linking early-stage “proto-LRD” binaries
to the broader AGN population and late-stage “LRD descendants” to coalescing binaries
detectable in GW experiments.
acknowledgement: We greatly thank Kenta Hotokezaka and Hanpu Liu for constructive
discussions. K.I., J.S., X.C., and L.C.H. acknowledge support from National Natural
Science Foundation of China (grant Nos. 12573015, 1251101148, 12233001, and 12473037),
the Beijing Natural Science Foundation (grant No. IS25003), and the China Manned
Space Program (grant No. CMS-CSST-2025-A09). J.S. is also supported by “The Fundamental
Research Funds for the Central Universities, Peking University” (grant No. 7100604896).
Z.H. acknowledges support by US NSF grant AST-2006176 and by NASA grant Nos. 80NSSC24K0440
and 80NSSC22K0822.
article_number: '25'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Kohei
full_name: Inayoshi, Kohei
last_name: Inayoshi
- first_name: Jinyi
full_name: Shangguan, Jinyi
last_name: Shangguan
- first_name: Xian
full_name: Chen, Xian
last_name: Chen
- first_name: Luis C.
full_name: Ho, Luis C.
last_name: Ho
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
orcid: 0000-0003-3633-5403
citation:
ama: Inayoshi K, Shangguan J, Chen X, Ho LC, Haiman Z. The emergence of Little Red
Dots from binary massive black holes. The Astrophysical Journal. 2026;1002(1).
doi:10.3847/1538-4357/ae548d
apa: Inayoshi, K., Shangguan, J., Chen, X., Ho, L. C., & Haiman, Z. (2026).
The emergence of Little Red Dots from binary massive black holes. The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae548d
chicago: Inayoshi, Kohei, Jinyi Shangguan, Xian Chen, Luis C. Ho, and Zoltán Haiman.
“The Emergence of Little Red Dots from Binary Massive Black Holes.” The Astrophysical
Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae548d.
ieee: K. Inayoshi, J. Shangguan, X. Chen, L. C. Ho, and Z. Haiman, “The emergence
of Little Red Dots from binary massive black holes,” The Astrophysical Journal,
vol. 1002, no. 1. IOP Publishing, 2026.
ista: Inayoshi K, Shangguan J, Chen X, Ho LC, Haiman Z. 2026. The emergence of Little
Red Dots from binary massive black holes. The Astrophysical Journal. 1002(1),
25.
mla: Inayoshi, Kohei, et al. “The Emergence of Little Red Dots from Binary Massive
Black Holes.” The Astrophysical Journal, vol. 1002, no. 1, 25, IOP Publishing,
2026, doi:10.3847/1538-4357/ae548d.
short: K. Inayoshi, J. Shangguan, X. Chen, L.C. Ho, Z. Haiman, The Astrophysical
Journal 1002 (2026).
date_created: 2026-05-10T22:02:14Z
date_published: 2026-05-01T00:00:00Z
date_updated: 2026-05-11T07:09:12Z
day: '01'
ddc:
- '520'
department:
- _id: ZoHa
doi: 10.3847/1538-4357/ae548d
external_id:
arxiv:
- '2505.05322'
file:
- access_level: open_access
checksum: b4506dfef3dd6da335775071d8f2a0a6
content_type: application/pdf
creator: dernst
date_created: 2026-05-11T07:07:22Z
date_updated: 2026-05-11T07:07:22Z
file_id: '21853'
file_name: 2026_AstrophysicalJour_Inayoshi.pdf
file_size: 3041897
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success: 1
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has_accepted_license: '1'
intvolume: ' 1002'
issue: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: The emergence of Little Red Dots from binary massive black holes
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1002
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21882'
abstract:
- lang: eng
text: The nature of little red dots (LRDs) has largely been investigated through
their continuum emission, with lines assumed to arise from a broad-line region.
In this paper, we instead use recombination lines to infer the intrinsic properties
of the central engine. Our analysis first reveals a tension between the ionizing
properties implied from Hα and He ii λ4686. The high Hα EWs require copious H-ionizing
photons, more than the bluest active galactic nucleus (AGN) ionizing spectra can
provide. In contrast, He ii emission is marginally detected, and its low EW is,
at most, consistent with the softest AGN spectra. The low He ii/Hβ (∼10−2, <20× local
AGN median) further points to an unusually soft ionizing spectrum. We extend our
analysis to dense gas envelopes (quasi-star/black-hole star) and find that hydrogen
recombination lines become optically thick and lose diagnostic power, but He ii
remains optically thin and a robust tracer. Photoionization modeling with Cloudy
rules out standard AGN accretion disk spectra. Alternative explanations include
exotic AGN with red rest-optical emission, high average optical depth (>10) from
gas/dust, and soft ionizing spectra with abundant H-ionizing photons, consistent
with, e.g., a cold accretion disk or a composite of AGN and stars. The latter
is an intriguing scenario since high hydrogen densities are highly conducive for
star formation, and nuclear star clusters are found in the vicinity of local massive
black holes. While previous studies have mostly focused on features dominated
by the absorbing hydrogen cloud, the He ii-based diagnostic proposed here represents
a crucial step toward understanding the central engine of LRDs.
acknowledgement: "B.W. thanks Michael Eracleous for valuable discussions. B.W. and
J.L. acknowledge support from JWST-GO-04233.009. B.W. also acknowledges support
provided by NASA through Hubble Fellowship grant HST-HF2-51592.001 awarded by the
Space Telescope Science Institute, which is operated by the Association of Universities
for Research in Astronomy, Inc., for NASA, under the contract NAS 5-26555. K.I.
acknowledges support from the National Natural Science Foundation of China (12573015,
W2532003), the Beijing Natural Science Foundation (IS25003), and the China Manned
Space Program (CMS-CSST-2025-A09). R.E.H. acknowledges support by the German Aerospace
Center (DLR) and the Federal Ministry for Economic Affairs and Energy (BMWi) through
program 50OR2403 “RUBIES.”\r\n\r\nThis work is based on observations made with the
NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski
Archive for Space Telescopes at the Space Telescope Science Institute, which is
operated by the Association of Universities for Research in Astronomy, Inc., under
NASA contract NAS 5-03127 for JWST. These observations are associated with program
# 1433, 2561, 4106, 4233, 5224, 6585. The specific observations analyzed can be
accessed via DOI: 10.17909/9hpc-nc45. Computations for this research were performed
on the Pennsylvania State University’s Institute for Computational and Data Sciences’
Roar supercomputer; and on computational resources managed and supported by Princeton
Research Computing, a consortium of groups including the Princeton Institute for
Computational Science and Engineering (PICSciE) and Research Computing at Princeton
University. Some of the stellar spectra are retrieved from the POLLUX database (pollux.oreme.org)
operated at LUPM (Université de Montpellier—CNRS, France) with the support of the
PNPS and INSU. This publication made use of the NASA Astrophysical Data System for
bibliographic information."
article_number: '10'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Bingjie
full_name: Wang, Bingjie
last_name: Wang
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Harley
full_name: Katz, Harley
last_name: Katz
- first_name: Kohei
full_name: Inayoshi, Kohei
last_name: Inayoshi
- first_name: Nikko J.
full_name: Cleri, Nikko J.
last_name: Cleri
- first_name: Anna
full_name: De Graaff, Anna
last_name: De Graaff
- first_name: Raphael E.
full_name: Hviding, Raphael E.
last_name: Hviding
- first_name: Pieter
full_name: Van Dokkum, Pieter
last_name: Van Dokkum
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Ivo
full_name: Labbé, Ivo
last_name: Labbé
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Ian
full_name: Mcconachie, Ian
last_name: Mcconachie
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: Erica J.
full_name: Nelson, Erica J.
last_name: Nelson
citation:
ama: 'Wang B, Leja J, Katz H, et al. The missing hard photons of Little Red Dots:
Their incident ionizing spectra resemble massive stars. The Astrophysical Journal.
2026;1003(1). doi:10.3847/1538-4357/ae5bab'
apa: 'Wang, B., Leja, J., Katz, H., Inayoshi, K., Cleri, N. J., De Graaff, A., …
Nelson, E. J. (2026). The missing hard photons of Little Red Dots: Their incident
ionizing spectra resemble massive stars. The Astrophysical Journal. IOP
Publishing. https://doi.org/10.3847/1538-4357/ae5bab'
chicago: 'Wang, Bingjie, Joel Leja, Harley Katz, Kohei Inayoshi, Nikko J. Cleri,
Anna De Graaff, Raphael E. Hviding, et al. “The Missing Hard Photons of Little
Red Dots: Their Incident Ionizing Spectra Resemble Massive Stars.” The Astrophysical
Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae5bab.'
ieee: 'B. Wang et al., “The missing hard photons of Little Red Dots: Their
incident ionizing spectra resemble massive stars,” The Astrophysical Journal,
vol. 1003, no. 1. IOP Publishing, 2026.'
ista: 'Wang B, Leja J, Katz H, Inayoshi K, Cleri NJ, De Graaff A, Hviding RE, Van
Dokkum P, Greene JE, Labbé I, Matthee JJ, Mcconachie I, Naidu RP, Nelson EJ. 2026.
The missing hard photons of Little Red Dots: Their incident ionizing spectra resemble
massive stars. The Astrophysical Journal. 1003(1), 10.'
mla: 'Wang, Bingjie, et al. “The Missing Hard Photons of Little Red Dots: Their
Incident Ionizing Spectra Resemble Massive Stars.” The Astrophysical Journal,
vol. 1003, no. 1, 10, IOP Publishing, 2026, doi:10.3847/1538-4357/ae5bab.'
short: B. Wang, J. Leja, H. Katz, K. Inayoshi, N.J. Cleri, A. De Graaff, R.E. Hviding,
P. Van Dokkum, J.E. Greene, I. Labbé, J.J. Matthee, I. Mcconachie, R.P. Naidu,
E.J. Nelson, The Astrophysical Journal 1003 (2026).
date_created: 2026-05-17T22:02:10Z
date_published: 2026-05-01T00:00:00Z
date_updated: 2026-05-18T08:18:39Z
day: '01'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae5bab
external_id:
arxiv:
- '2508.18358'
file:
- access_level: open_access
checksum: ee9ebc8ae2304fec04f24b82ebaac8bc
content_type: application/pdf
creator: dernst
date_created: 2026-05-18T08:17:26Z
date_updated: 2026-05-18T08:17:26Z
file_id: '21891'
file_name: 2026_AstrophysicalJourn_Wang.pdf
file_size: 2584417
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success: 1
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intvolume: ' 1003'
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language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'The missing hard photons of Little Red Dots: Their incident ionizing spectra
resemble massive stars'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1003
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21930'
abstract:
- lang: eng
text: "We present the discovery of extreme nitrogen enrichment by Wolf Rayet nitrogen
(WN) stars in the metal-poor (∼10%Z⊙), lensed, compact (Reff ∼ 20 pc) galaxy RXCJ2248
at z = 6.1, revealed by unprecedentedly deep\r\nJWST/NIRSpec medium-resolution
spectroscopy from the GLIMPSE-D Survey. The exquisite signal-to-noise\r\nratio
reveals multiple high-ionization nebular lines and broad Balmer and [O III] components
(FWHM\r\n∼700–3000 km s\r\n−1\r\n). We detect broadened He II λ1640 and λ4687
(FWHM ∼ 530 km s\r\n−1\r\n) and strong N III λ4642\r\nemission consistent with
a population of WN stars, making RXCJ2248 the most distant galaxy with confirmed\r\nWolf
Rayet (WR) features to date. We measure the multiphase nebular density across
five ions, the direct-method\r\nmetallicity (\r\n12 + log(O/H) = 7.753 ± 0.025\r\n),
and a nonuniform elemental enrichment pattern of extreme N/O\r\nenhancement (\r\nlog(N/O)
= 0.391 ± 0.037\r\nfrom N+, N+2\r\n, and N+3\r\n) but suppressed C/O relative
to empirical\r\nC/N trends. We show that this abundance pattern can be explained
by enrichment from a dual-burst with a low\r\nWR carbon/WN ratio, as expected
at low metallicities. Crucially, these signatures can only arise during a brief,\r\nrare
evolutionary window shortly after a burst (∼3–6 Myr), when WN stars dominate chemical
feedback but\r\nbefore dilution by later yields (e.g., supernovae). The observed
frequency of strong N emitters at high−z implies a\r\n∼50 Myr burst duty cycle,
suggesting that N/O outliers may represent a brief but ubiquitous phase in the\r\nevolution
of highly star-forming early galaxies. The WN detection in RXCJ2248, therefore,
provides the first\r\ndirect evidence of WR-driven nitrogen enrichment in the
first billion years of the Universe and a novel timing\r\nargument for the bursty
star formation cycles that shaped galaxies at cosmic dawn."
acknowledgement: "\r\nThe American Astronomical Society, find out more.\r\n\r\nThe
following article isOpen access\r\nA Fleeting GLIMPSE of N/O Enrichment at Cosmic
Dawn: Evidence for Wolf Rayet N Stars in a z = 6.1 Galaxy\r\nDanielle A. Berg, Rohan
P. Naidu, John Chisholm, Hakim Atek, Seiji Fujimoto, Vasily Kokorev, Lukas J. Furtak,
Chiaki Kobayashi, Daniel Schaerer, Angela Adamo, Qinyue Fei, Damien Korber, Jorryt
Matthee, Rui Marques-Chaves, Zorayda Martinez, Kristen. B. W. McQuinn, Julian B.
Muñoz, Pascal A. Oesch, Alberto Saldana-Lopez, Daniel P. Stark, Mabel G. Stephenson,
and Tiger Yu-Yang HsiaoHide full author list\r\n\r\nPublished 2026 May 20 • © 2026.
The Author(s). Published by the American Astronomical Society.\r\nThe Astrophysical
Journal, Volume 1003, Number 2\r\nCitation Danielle A. Berg et al 2026 ApJ 1003
112\r\nDOI 10.3847/1538-4357/ae5e4c\r\n\r\nDownloadArticle PDFDownloadArticle ePub\r\nAuthors\r\nFigures\r\nTables\r\nReferences\r\nArticle
data\r\nDownload PDFDownload ePub\r\nArticle metrics\r\n173 Total downloads\r\n\r\nShare
this article\r\nArticle information\r\nAbstract\r\nWe present the discovery of extreme
nitrogen enrichment by Wolf Rayet nitrogen (WN) stars in the metal-poor (∼10%Z⊙),
lensed, compact (Reff ∼ 20 pc) galaxy RXCJ2248 at z = 6.1, revealed by unprecedentedly
deep JWST/NIRSpec medium-resolution spectroscopy from the GLIMPSE-D Survey. The
exquisite signal-to-noise ratio reveals multiple high-ionization nebular lines and
broad Balmer and [O iii] components (FWHM ∼700–3000 km s−1). We detect broadened
He ii λ1640 and λ4687 (FWHM ∼ 530 km s−1) and strong N iii λ4642 emission consistent
with a population of WN stars, making RXCJ2248 the most distant galaxy with confirmed
Wolf Rayet (WR) features to date. We measure the multiphase nebular density across
five ions, the direct-method metallicity (\r\n), and a nonuniform elemental enrichment
pattern of extreme N/O enhancement (\r\n from N+, N+2, and N+3) but suppressed C/O
relative to empirical C/N trends. We show that this abundance pattern can be explained
by enrichment from a dual-burst with a low WR carbon/WN ratio, as expected at low
metallicities. Crucially, these signatures can only arise during a brief, rare evolutionary
window shortly after a burst (∼3–6 Myr), when WN stars dominate chemical feedback
but before dilution by later yields (e.g., supernovae). The observed frequency of
strong N emitters at high−z implies a ∼50 Myr burst duty cycle, suggesting that
N/O outliers may represent a brief but ubiquitous phase in the evolution of highly
star-forming early galaxies. The WN detection in RXCJ2248, therefore, provides the
first direct evidence of WR-driven nitrogen enrichment in the first billion years
of the Universe and a novel timing argument for the bursty star formation cycles
that shaped galaxies at cosmic dawn.\r\n\r\nExport citation and abstract\r\nBibTeXRIS\r\n\r\nPrevious
article in issue\r\nNext article in issue\r\n\r\nOriginal content from this work
may be used under the terms of the Creative Commons Attribution 4.0 licence. Any
further distribution of this work must maintain attribution to the author(s) and
the title of the work, journal citation and DOI.\r\n\r\n1. Introduction\r\nA key
tracer of galaxy evolution is the change in their chemical composition over time.
The metallicity of a galaxy is a sensitive observational diagnostic of its past
star formation history and present-day evolutionary state given that metallicity
increases with each successive generation of massive star yields (e.g., M. Tosi
1988; J.-R. Roy & D. Kunth 1995; D. A. Berg et al. 2019; R. Maiolino & F. Mannucci
2019). Oxygen is an important tracer of metallicity because it is the most abundant
element in the Universe after H and He and is convenient to observe, with ubiquitous
emission lines from H ii regions in the rest-frame optical regime. While O emission
in dwarf and spiral galaxies has been widely observed in the rest-frame optical
and UV (e.g., R. C. Kennicutt 1992; Y. I. Izotov & T. X. Thuan 1999; L. van Zee
& M. Haynes2006; D. A. Berg et al. 2012, 2016, 2019; P. Senchyna et al. 2017; N.
S. J. Rogers et al. 2022), the N emission in these same galaxies has been predominantly
traced only in the optical through the low-ionization [N ii] λλ6550,6585 emission
lines. In general, there is a surprising dearth of detections of the high-ionization
N emission counterparts in local galaxies, totaling less than 10 galaxies with significant
detections of either N iv] λλ1483,1486 or N iii] λ1750 (e.g., M. Mingozzi et al.
2022; Z. Martinez et al. 2025). However, with the advent of JWST, there is a growing
prevalence of z ≳ 5 galaxies with extreme properties, including intense UV N emission
(e.g., A. J. Bunker et al. 2023; Y. Isobe et al. 2023; M. Castellano et al. 2024;
T. Y.-Y. Hsiao et al. 2024; X. Ji et al. 2024; R. Marques-Chaves et al. 2024; D.
Schaerer et al. 2024; M. Curti et al. 2025a; Y. Harikane et al. 2025a; R. P. Naidu
et al. 2026; M. W. Topping et al. 2025b).\r\n\r\nThe first noted, and one of the
most distant, examples of extreme rest-frame UV N emission comes from the spectroscopically
confirmed z = 10.6 galaxy, GN-z11. JWST spectra of GN-z11 revealed surprisingly
strong N iv] λλ1483,1486 and N iii] λ1750 emission (e.g., A. J. Bunker et al. 2023)
that corresponds to supersolar nitrogen-to-oxygen (N/O) enrichment (\r\n; e.g.,
A. J. Cameron et al. 2023). Subsequently, enhanced N/O has been reported in a number
of high−z galaxies, including GDS 3073 (z = 5.55; X. Ji et al. 2024), RXCJ2248-ID
(z = 6.10; M. W. Topping et al. 2024), A1703-zd6 (z = 7.04; M. W. Topping et al.
2025b), CEERS-1019 (z = 8.68; R. Marques-Chaves et al. 2024), GNz9p4 (z = 9.38;
D. Schaerer et al. 2024), GHZ9 (z = 10.15; L. Napolitano et al. 2025), GHZ2 (z =
12.34; M. Castellano et al. 2024), and MoM-z14 (z = 14.44; R. P. Naidu et al. 2026).
For a review of nitrogen line detections, see D. P. Stark et al. (2025). Such strong
nebular N+3 emission requires a relatively hard ionizing radiation field (≳47.4
eV), where models of massive stars predict few photons. On the other hand, N+2 has
a lower ionization potential (∼29.6 eV), but statistically significant detections
are strikingly rare in integrated galaxy spectra (e.g., D. A. Berg et al. 2018;
M. Mingozzi et al. 2022; A. J. Bunker et al. 2023; P. Senchyna et al. 2024) and
are only expected to be strong at the highest possible nebular temperatures (∼2.5
× 104 K). Furthermore, the timing of the incredibly high N/O abundances reported
for the high-redshift UV N emitters just a few 100 Myr after the Big Bang is unexpected.\r\n\r\nThe
discovery of significant, rapid nitrogen enhancement so early in the Universe was
surprising because it contradicts our longstanding understanding of N production.
In typical chemical evolution modeling, some nitrogen enrichment can occur early
on via core collapse supernova (CCSN), but substantial nitrogen enrichment only
occurs 100 s of megayears after the onset of star formation via asymptotic giant
branch (AGB) stars (e.g., F. Vincenzo et al. 2019; C. Kobayashi et al. 2020). Thus,
alternative, faster enrichment methods are needed to explain substantial nitrogen
enrichment in early galaxies. As a result, the necessary ionizing flux and conditions
to produce the unexpectedly strong N+3 and N+2 emission observed in galaxies beyond
z ∼ 5 have been attributed to more extreme sources, such as active galactic nuclei
(AGN; R. Maiolino et al. 2024), Wolf Rayet (WR) stars (e.g., P. Senchyna et al.
2024; K. Watanabe et al. 2024; M. L. P. Gunawardhana et al. 2025), globular cluster
precursors (e.g., C. Charbonnel et al. 2023; X. Ji et al. 2026), super star clusters
(e.g., M. Pascale et al. 2023), very massive stars (VMSs: M⋆ > 102 M⊙; e.g., J.
S. Vink 2023; Y. Shi et al. 2026), or supermassive stars (M⋆ > 103 M⊙; e.g., C.
Charbonnel et al. 2023; C. Nagele & H. Umeda 2023), tidal disruption events (e.g.,
A. J. Cameron et al. 2023; K. Watanabe et al. 2024), and more.\r\n\r\nMost of our
understanding of WR stars has been built from observations of individual resolved
stars in a handful of galaxies in the Local Group, with almost no direct spectroscopic
evidence for the prevalence of WR stars in more distant galaxies. To date, only
two systems at Cosmic Noon (z ≈ 2–3) have confirmed signatures of WR stars: MARTA-4327
at z = 2.224 (hereafter, M4327; M. Curti et al. 2025b) and the Sunburst Arc at z
= 2.37 (T. E. Rivera-Thorsen et al. 2024). Extending such detections to earlier
cosmic epochs is crucial for understanding the role of massive stars in shaping
the chemical evolution of galaxies in the first Gyr.\r\n\r\nHere, we investigate
the z = 6.1 lensed galaxy RXCJ2248-ID3. RXCJ2248-ID was first identified by F. Boone
et al. (2013), I. Balestra et al. (2013), and A. Monna et al. (2014) and discovered
to be a high-ionization, compact, metal-poor, N-enhanced galaxy by R. Mainali et
al. (2017), K. B. Schmidt et al. (2017), and M. W. Topping et al. (2024). We present
extremely deep JWST/NIRSpec observations of RXCJ2248-ID3 that provide the highest-redshift
spectroscopic evidence of WR nitrogen (WN) stars to date, which provide a physically
consistent mechanism driving its extreme nitrogen enrichment (M. W. Topping et al.
2024). The remainder of this paper is organized as follows. The observations and
data reduction are briefly described in Section 2.1, followed by a description of
the emission-line fits, including the broad lines related to the WR feedback, in
Section 2.2. We present the discovery of WN stars at z ∼ 6 via their spectral signatures
in Section 3. We determine new nebular properties and O, C, N, and Si abundances
in Section 4.3 and compare them to populations of both low- and high-redshift galaxies.
We discuss the source of N enrichment in the early Universe and subsequently estimate
mass production and timing arguments in Section 5. Finally, we present our conclusions
in Section 6. Throughout this work, we adopt cosmological parameters of H0 = 70
km s−1 Mpc−1, Ωm = 0.30, and ΩΛ = 0.7 and the solar abundance pattern from M. Asplund
et al. (2021).\r\n\r\n2. JWST/NIRSpec Spectra\r\nRXCJ2248 is a galaxy at z ∼ 6.1
that is lensed into multiple images by the Abell S1063 cluster (α = 22:48:44.13,
δ =−44:31:57.50) at a redshift of z = 0.348. We present an analysis of the brightest
image, RXCJ2248-ID3 (J = 25.0), which has a magnification of μ ∼ 7 (L. Furtak et
al. 2025). RXCJ2248-ID was discovered as a z ∼ 6 candidate (F. Boone et al. 2013;
A. Monna et al. 2014) using the 16-band HST photometry of the CLASH Survey and spectroscopically
confirmed via VIsible Multi-Object Spectrograph (VIMOS)/VLT observations by I. Balestra
et al. (2013). RXCJ2248-ID3 was soon found to be an exciting extreme emission-line
galaxy via ground-based spectroscopy (R. Mainali et al. 2017), with strong detections
of high-ionization emission such as O iii] λλ1661,1666 and C ivλλ1548,1550 but no
He ii, suggesting star formation as the ionizing source rather than an AGN.\r\n\r\nThe
early spectra of RXCJ2248-ID3 motivated further rest-UV+optical study with JWST/NIRSpec
by M. W. Topping et al. (2024). This work performed direct metallicity calculations
to show that RXCJ2248-ID3 is one of the most extreme N/O-enhanced (), metal-poor
() galaxies, with high-ionization ([O iii] λ5008/[O ii] λ3728 = 184) and high nebular
density (6.4 × 104 ≤ ne(cm−3) ≤3.1 × 105). They also used spectral energy distribution
(SED) fitting with a constant star formation history to characterize its low stellar
mass (M⋆ ∼ 108 M⊙) and the young-massive star population (∼2 Myr) of RXCJ2248. M.
W. Topping et al. (2024), therefore, suggest that the N/O enrichment may be due
to a short-lived phase that many z > 6 bursty galaxies experience. In this paper,
we build on the work of M. W. Topping et al. (2024) with new, extraordinarily deep
rest-optical JWST/NIRSpec observations of RXCJ2248-ID3 from the GLIMPSE-D Survey,
a Director’s Discretionary Time (DDT) follow-up program described below.\r\n\r\n2.1.
Observations and Reduction\r\nThe work presented here uses both the rest-UV JWST/NIRSpec
archival spectra from JWST PID 2478 (PI Stark) and new rest-optical JWST/NIRSpec
spectra from the GLIMPSE-D Survey, which is an extension of the GLIMPSE Survey.
Properties of RXCJ2248-ID and observation details are presented in Table 1.\r\n\r\nTable
1. Properties of RXCJ2248-ID3\r\n\r\nJWST/NIRSpec Observations\r\nGrating/Filter\t(s)\tPI/PID\r\nG140M/F100LP\t6215\tStark/2478\r\nG235M/F170LP\t1576\tStark/2478\r\nG395M/F290LP\t107,228\tFujimoto
& Naidu/9223\r\nMeasured Properties\r\nProperty\tValue\tReferences\r\nR.A.\t+22:48:45.81\tThis
work\r\nDecl.\t−44:32:14.95\tThis work\r\nz\t6.1025 ± 0.0013\tThis work\r\nμ\t6.8877\tL.
Furtak et al. (2025)\r\nReff (pc)\t\tA. Claeyssens (2025)\r\nM⋆ (M⊙)\t\tA. Claeyssens
(2025)\r\nΣ⋆ (M⊙ pc−2)\t\tA. Claeyssens (2025)\r\nSFRHα (M⊙ yr−1)\t3.2\tThis work,
Section 5.3\r\nSFRSED,1Myr\t4.7\tA. Claeyssens (2025)\r\nSFRSED,10Myr\t4.1\tA. Claeyssens
(2025)\r\nΣSFR (M⊙ yr−1 kpc−2)\t1.34 × 103\tThis work\r\ntage (Myr)\t\tA. Claeyssens
(2025)\r\n12+log(O/H)\t7.753 ± 0.025\tThis work, Section 4.3.1\r\nlog(N/O)\t−0.391
± 0.037\tThis work, Section 4.3.2\r\nNote. Top: JWST/NIRSpec observations of RXCJ2248-ID3,
including archival observations from PID 2478 (PI: Stark) and very deep GLIMPSE-D
observations from PID 9223 (PI: Fujimoto & Naidu). Columns (1)–(3) list the grating/filter,
exposure time, and principle investigator/PID. Bottom: Measured global properties
of RXCJ2248-ID3. The R.A. and decl. are the extraction coordinates for RXCJ2248-ID3.
The redshift was determined from the GLIMPSE-D spectrum emission lines. GLIMPSE
imaging was used to determine the lensing model magnification, μ. Effective radius
of the RXCJ2248-ID3 clump, stellar mass, and current massive star population age
are from the SED modeling of A. Claeyssens (2025), while the SFR was determined
from both the SED fitting and the narrow-component, collisions-corrected Hα flux
(see Section 5.3), all corrected for the lensing factor. The star formation rate
surface density was determined using the SFRHα. The metallicity and relative N/O
abundance were determined using the direct method.\r\n\r\nDownload table as: \r\nASCIITypeset
image\r\n\r\nThe GLIMPSE Survey is a large Cycle 2 JWST program (PID 3293; PIs Atek
& Chisholm) that performed ultradeep NIRCam imaging (∼30.8 mag at 5σ over 0.8–5
μm) in seven broadband and two medium-band filters of the lensing cluster Abell
S1063 (H. Atek et al. 2025). A. Claeyssens (2025) performed size and photometric
measurements of RXCJ2248-ID in the different multiple images. The SED fitting was
performed with the Bayesian Analysis of Galaxies for Physical Inference and Parameter
Estimation (BAGPIPES; A. C. Carnall et al. 2018) code with Binary Population and
Spectral Synthesis (BPASS v2.14, J. J. Eldridge et al. 2017) stellar population
synthesis burst models and cloudy v23.01 photoionization models (M. Chatzikos et
al. 2023; C. M. Gunasekera et al. 2023). Priors were used to be physically consistent
with the source, i.e., high-ionization parameter (), low extinction (Av < 0.5 mag),
low metallicity (Z < 0.4 Z⊙), and bursty star formation (τ = 1 Myr, i.e., close
to a single burst, or τ = 10 Myr). The resulting best fit has a young age ( Myr)
and low stellar mass of but within a compact size of pc such that the stellar mass
surface density is . This value is akin to the highest densities found in globular
clusters, similar to the ones reported for young star clusters and clumps at high
redshift (A. Claeyssens et al. 2025; M. Messa et al. 2026), and broadly consistent
with the conclusions presented in M. W. Topping et al. (2024).\r\n\r\nSubsequent
medium-resolution (R ∼ 1000) spectra of RXCJ2248-ID3 were obtained as part of the
follow-up GLIMPSE-D Survey: JWST DDT Program 9223 (PIs Fujimoto & Naidu) targeting
a Pop III candidate in S. Fujimoto et al. (2025) using NIRSpec Multi-Object Spectroscopy
(MOS) with the G395M grating and F290LP filter. As part of this program, RXCJ2248-ID3
was observed for a total of 13 exposures using a 3-point nod pattern and NRSIRS2
readout, totaling ∼30 hr of integration. The MSA slit positions covering RXCJ2248-ID3
of the three pointings are shown in Figure 1.\r\n\r\nZoom InZoom OutReset image
size\r\nFigure 1. JWST/NIRSpec MSA slits targeting RXCJ2248-ID3 for each of the
three exposures in the GLIMPSE-D program. The two pointings that are closely aligned
(solid purple regions) have the same wavelength coverage, while the pointing offset
to the lower left (dashed region) has somewhat reduced blue coverage. All three
pointings were used in the spectrum coaddition.\r\n\r\nDownload figure:\r\n\r\nStandard
imageHigh-resolution image\r\nWe augment the rest-optical GLIMPSE-D data with archival
rest-far-UV G140M/F100LP and rest-near-UV G235M/F170LP observations from PID 2478
(PI Stark), covering the rest-frame ∼1400–4000 Å range. This program also observed
the G395M/F290LP setting, but we only use the significantly deeper GLIMPSE-D G395M
observations here. Multiple images of RXCJ2248 were identified and observed in program
#2478. M. W. Topping et al. (2024) utilized these data by coadding the spectra of
the individual images. In contrast, only the brightest image (ID3) was observed
in the GLIMPSE-D Survey. To ensure consistency, we therefore restricted our analysis
to the G140M and G235M spectra of ID3 obtained in program #2478. As a result, our
G140M and G235M measurements are not directly comparable to those presented by M.
W. Topping et al. (2024).\r\n\r\nThe data were reduced using v0.9.8 of the msaexp
pipeline (G. Brammer 2022), following the standard routines described in A. de Graaff
et al. (2025), K. E. Heintz et al. (2025), and F. Valentino et al. (2025). Briefly,
level-2 calibrated products from MAST are subject to a series of custom corrections
that account for, e.g., 1/f noise, bar vignetting, and detector bias. We used the
“local” nodded background subtraction. The 2D spectra were drizzled onto a common
wavelength grid and 1D spectra were optimally extracted using a profile model that
accounts for, e.g., the wavelength-dependent PSF and offsets from the nominal position
expected from the catalog. Line centers were measured for the strongest emission
lines in the G395M spectrum (i.e., Hδ, Hγ, [O iii] λ4364, Hβ, [O iii] λλ4960,5008,
He iλ5877, Hα, He iλ7067) and used to determine a redshift of z = 6.1025 ± 0.0013.
Note that the bluest portion of the G395M tends to favor a slightly lower redshift
(i.e., z ∼ 6.1000), while the reddest portion favors a slightly higher redshift
(i.e., z ∼ 6.1034). The three individual 1D extracted spectra were then normalized
to the common continuum flux scale of the first spectrum at rest-wavelengths of
∼6000–62000 Å prior to coadding. Spectral coaddition was performed as a weighted
average using the inverse variance as the weight.\r\n\r\nThe resulting spectrum,
shown in Figure 2, covers an observed wavelength range ∼2.8–5.5 μm, which corresponds
to a rest-optical range of ∼3900–7740 Å. Note that the third pointing (dashed slits
in Figure 1) has reduced wavelength coverage such that the blue end begins at ∼4265.
The deep GLIMPSE-D spectra provide unparalleled signal-to-noise ratio (S/N; >5 at
5100 Å continuum) that enable rest-optical diagnostics typically reserved for nearby
galaxies.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 2. JWST/NIRSpec rest-frame
UV and optical spectra of RXCJ2248-ID3 highlighting the first object known with
simultaneously detected emission from N+, N+2, and N+3 (see, also, M. W. Topping
et al. 2024) and WR features. The second row shows the main emission UV emission-line
detections from the archival G140M/F100LP spectrum, with significant detections
of several high-ionization emission lines, including N iv] λλ1483,1486, C iv λλ1548,1550,
He ii λ1640, O iii] λλ1661,1666, N iii] λ1750, and C iii] λλ1907,1909. The third
row shows the blue end of the optical spectrum, where the left-hand panel shows
the archival G235M/F170LP spectrum, which includes the low-ionization [O ii] λλ3727,3730
doublet. The right-hand panel of the third row and the fourth row shows the extremely
high S/N GLIMPSE-D optical spectrum, enabling detections of several weak features.
Note that some of the important features to this work are highlighted in the zoom
in panels in the top row. In particular, the last panel reveals the most distant
WR detection to date, with the λ4650 WR bump showing emission from N iii λ4642,
indicative of nitrogen enrichment from WN stars. Note that not all of the labeled
lines correspond to line detections.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution
image\r\n2.2. Emission-line Measurements\r\nIn order to perform a consistent analysis
of our data, we measure emission-line fluxes for both the archival spectra and the
new GLIMPSE-D spectra presented here. We fit neighboring emission lines simultaneously
using Gaussian profiles with the lmfit package (M. Newville et al. 2015) in Python.
Purely nebular lines (i.e., lines without possible stellar contributions or resonant
effects) close in wavelengths were constrained to have the same full width at half-maximum
(FWHM) velocity widths. Additionally, the relative wavelength spacing between lines
was constrained to laboratory values and doublets with constant flux ratios set
by atomic physics were constrained to their theoretical values, with small uncertainty
allowances. The uncertainties on the line fluxes were estimated as the standard
error derived from the least-squares minimization in lmfit, which considers the
uncertainty on the Gaussian profile and linear continuum.\r\n\r\nBroad emission
components are clearly visible at the base of some of the emission lines in the
GLIMPSE-D spectrum of RXCJ2248-ID3. Such broad emission features can be produced
by stellar winds, shocks, or turbulence. Since He iiλ1640 and λ4687 emission lines
can be affected by stellar winds, we fit these features with an unconstrained Gaussian
width. Using the jwst-msa package (A. de Graaff et al. 2024), we deconvolved all
measured FWHMs with the modeled wavelength-dependent line spread function (LSF).
We found the He ii lines to be broadened compared to purely nebular lines. For the
He iiλ 4687 line, the velocity width is 528 ± 100 km s−1, which is more than two
times broader than the narrow nebular Hβ component with vFWHM = 243 ± 25 km s−1.\r\n\r\nThe
strongest rest-optical H (Hγ, Hβ, and Hα) and [O iii] (λ4364, λλ4960,5008) emission
lines have complex profiles with both narrow and broad emission components. Such
broad components may also be present in the rest-UV and fainter rest-optical emission
lines, but none are obvious given the lower S/N of these emission features and/or
underlying continuum. To fit these profiles, we tested three different multicomponent
profile combination fits for the Hα + [N ii] complex. For all three fits, the narrow
Hα and [N ii] λλ6550,6585 lines were fit by Gaussians with a single velocity width,
but the broad component was fit with either: (1) a single Gaussian profile, (2)
two Gaussian profiles, or (3) a single exponential profile. The single broad Gaussian
profile fit had strong residuals near the center of the broad component, so did
not provide a good fit to the observed emission profile. Both the double Gaussian
profile and the exponential profile provided relatively good visual fits, but the
double Gaussian fit had a lower reduced chi-squared ( vs ) and Bayesian inference
criteria (BIC2Gauss = 36 versus (BICexp. = 87), and so was adopted as the better
statistical fit.\r\n\r\nThe right panel of Figure 3 shows the best multicomponent
fit to the Hα + [N ii] complex. Since all kinematically similar lines in the Balmer
emission series arise from the same gas, we expect the Hβ and Hγ profiles to be
well fit by scaling the Hα best fit. Therefore, we constrained the velocity widths
of the Hβ and Hγ emission components to match the narrow + double broad Gaussian
Hα fit, accounting for the wavelength-dependent LSF. We found excellent fit results,
with similarly small reduced-χ2 and BIC values. This means that the H i lines are
well fit by a profile with (1) a strong, narrow (∼250 km s−1) nebular component,
(2) a moderate (∼20% of total flux), broad component (∼670 km s−1), and (3) a weak
(∼10% of total flux), very broad (∼2530 km s−1) component.\r\n\r\nZoom InZoom OutReset
image size\r\nFigure 3. Multicomponent emission-line fits to the GLIMPSE spectrum
of RXCJ2248-ID for Hα λ6565 + [N II] λλ6549,6585 (left panels), Hβ λ4863 + [O III]
λλ4960,5008 (middle panels), and Hγ λ4342 + [O III] λ4364 (right panels). When fit
with single, narrow Gaussian components (e.g., purple and yellow filled Gaussians),
all three line complexes show strong, broad component residual flux. The resulting
best fit to each line is comprised of a single narrow Gaussian plus two broad Gaussians,
where the relevant component velocity widths are tied together: The Hα λ6565 + [N
ii] λλ6549,6585 complex fit provided the velocity width constraints for the H Balmer
line narrow (purple Gaussians) and broad components (blue and green Gaussians) and,
subsequently, the Hβ λ4863 + [O iii] λλ4960,5008 fit constrained the [O iii] narrow
(yellow Gaussian) and broad (orange and red Gaussians) velocity widths that were
then used in the Hγ λ4342 + [O iii] λ4364 fit. Note that additional faint lines
(e.g., He i λ5017) were included in the fit in the middle panel. Careful accounting
for the residual broad flux has a significant impact on the derived nebular reddening,
temperature, metallicity, and N/O abundance.\r\n\r\nDownload figure:\r\n\r\nStandard
imageHigh-resolution image\r\nThe [O iii] λλ4960,5008 doublet lines are also well
fit by a narrow Gaussian plus double Gaussian broad component profile, with the
relative fluxes of each component constrained to the theoretical ratio. While the
narrow-component FWHM was set to the velocity width of the narrow Balmer lines,
convolved with the LSF, we allowed the FWHM of the two broad [O iii] components
to vary freely and found widths of ∼890 km s−1 and ∼2980 km s−1, respectively. The
similarity between the [O iii] and H i velocity widths of the broad components argues
against emission from an AGN directly (where high densities cause collisional de-excitation
of [O iii]) and is more consistent with stellar or AGN driven winds (e.g., Y. I.
Izotov & T. X. Thuan 2008; G. Gräfener & J. S. Vink2015; G. Gräfener et al. 2017;
C. J. Burke et al. 2021). Interestingly, the broad components of the H i lines compose
a larger fraction of their total flux (∼20% and 10%, respectively) than [O iii]
(∼10% and 5%, respectively).\r\n\r\nThe resulting fit to the Hβ + [O iii] λλ4960,5008
complex is shown in the middle panel of Figure 3 to be an excellent fit, with minimal
residuals. The exquisite S/N of the GLIMPSE spectrum also reveals broad wings on
the [O iii] λ4364 profile, as seen in the left panel of Figure 3. Therefore, we
also applied the narrow Gaussian plus double Gaussian broad component profile to
[O iii] λ4364, constraining the velocity widths to the values measured for [O iii]
λλ4960,5008.\r\n\r\nDouble broad components with similar velocity widths (750 and
2500 km s−1, respectively) are seen in the z ∼ 0 extreme emission-line galaxies,
J1044+0353 and J1418+2102, reported in D. A. Berg et al. (2021). However, each broad
component observed in these nearby analogs only accounts for 1%–3% of the total
H i flux. This sort of broad component emission from the Balmer H and [O iii] lines
with widths (1000–2000 km s−1) and fractional fluxes of 1%–2% is commonly found
in spectra of blue compact dwarf galaxies (BCDs; e.g., Y. I. Izotov et al. 2006,
2007). This suggests that bulk motion of the gas is typical in these metal-poor,
bursty environments, but for a larger mass of gas in RXCJ2248-ID3.\r\n\r\nThe sensitive
accounting of broad component emission afforded by the deep GLIMPSE-D spectra is
important because even a small fraction of broad emission around H emission line
can significantly affect the fit to weak lines such as [N ii] λλ6550,6585 (e.g.,
D. A. Berg et al. 2021). In RXCJ2248-ID, the broad components compose a significant
fraction of the total H and [O iii] fluxes, and so are critical to properly measure
not only the [N ii] λ6585 emission but also the [O iii] λ4364, Hβ, [O iii] λλ4960,5008,
and Hα narrow-line fluxes. For this reason, we adopt the narrow-line fluxes from
our best multicomponent fits for the remaining analysis; we reserve further investigation
of the the broad emission for a forthcoming paper.\r\n\r\nAs noted above, the UV
spectra do not have sufficient S/N to decompose narrow and possible broad components.
As a result, density diagnostics and relative abundance ratios determined from UV
line ratios may include contributions from multiple kinematic components. If the
broad components arise from gas with distinct physical conditions, this could introduce
systematic offsets. We test the level of bias possible due to broad component contamination
of narrow-line fluxes by adopting the relative narrow and broad component profiles
of [O iii] λ5008 as a template for collisionally excited lines. The broad component
areas overlap with the narrow profile such that the broad components are responsible
for 8.6% and 2.2% of the narrow-component flux, or 10.8% in total. We use this fraction
to set the upper contamination limit of potential broad components to the UV emission
lines and determine the impact on nebular density, temperature, and abundance calculations
in Section 4.4.\r\n\r\n2.3. Reddening Correction\r\nThe observed Balmer decrement
of the narrow Hα/Hβ lines is FHα/FHβ = 3.48, implying either a moderate amount of
dust is present or collisional enhancement of Hα. This value disagrees with the
results of M. W. Topping et al. (2024), who measured an observed decrement of 2.55
± 0.05 that they found to be consistent with no dust attenuation. Similarly, A.
Crespo Gómez et al. (2025) used high-resolution NIRSpec/G395H data to fit multiple
component Balmer decrements for RXCJ2248-ID3, finding a narrow-component FHα/FHβ
= 2.7 that is consistent with no attenuation, but broad- and very broad-component
decrements of 4.3 and 6.6, respectively, that imply differential extinction. We
too find higher FHα/FHβ ratios for the broad components, but the source of this
increase is not clear; it could indicate higher dust in the broad component gas,
as suggested by A. Crespo Gómez et al. (2025), or result from significant collisional
enhancement of Hα.\r\n\r\nFortunately, the GLIMPSE-D spectrum provides a significant
increase in S/N in the continuum, allowing for more robust fitting of broad components,
including in the Hγ and [O iii] λ4364 and λ5008 lines. Fitting the broad components
directly in the [O iii] lines offers the advantage over previous works that we do
not need to correct for broad component contamination with differential extinction
in our Te calculation. Furthermore, by fitting the broad components in Hγ we were
able to examine the narrow-component Hβ/Hγ ratio, finding a decrement of FHβ/FHγ
= 2.16 that is consistent with very little dust (see Table 2). Note that we do not
consider the Hβ/Hδ ratio here because the Hδ line is not strong enough to robustly
fit the broad components in a consistent manner with the profile fitting of the
Hγ, Hβ, and Hα lines.\r\n\r\nTable 2. Rest UV+Optical Emission-Line Fluxes\r\n\r\nIon+Wavelength\tI(λ)/I(C
iii])\tEW\r\n(Å)\t \t(Å)\r\nN iv] λ1483.33\t42.78 ± 1.61\t6.67\r\nN iv] λ1486.50\t102.0
± 0.82\t15.9\r\nHe iiλ1640.42\t22.46 ± 197\t4.88\r\nO iii] λ1666.15\t85.84 ± 0.59\t18.9\r\nN
iii] λ1750a\t38.59 ± 0.64\t9.18\r\nSi iii] λ1883.00\t5.01 ± 3.25\t1.32\r\nSi iii]
λ1892.03\t8.25 ± 1.98\t2.21\r\nC iii] λ1906.68\t35.11 ± 0.31\t9.65\r\n[C iii] λ1908.73\t64.89
± 0.25\t17.9\r\nIon+Wavelength\tI(λ)/I(Hβ)\tEW\r\n(Å)\t \t(Å)\r\n[O ii] λ3728a\t4.09
± 2.05\t6.22\r\nHγ λ4341.66b\t47.41 ± 3.07\t73.8\r\n[O iii] λ4364.44b\t42.45 ± 1.92\t66.5\r\nHe
i λ4472.73\t8.90 ± 0.39\t27.8\r\nN iii λ4641.94\t1.40 ± 0.20\t4.4\r\nHe ii λ4687.01\t1.33
± 0.29\t4.2\r\n[Ar iv] λ4712.69c\t2.30 ± 0.27\t10.3\r\nHe i λ4714.46c\t1.91 ± 0.19\t3.0\r\n[Ar
iv] λ4741.49\t4.10 ± 0.26\t13.0\r\nHβ λ4862.71b\t100.0 ± 4.4\t356\r\n[O iii] λ4960.29b\t230.5
± 9.0\t877\r\n[O iii] λ5008.24b\t708.9 ± 27.5\t2791\r\nHα λ6564.60b,d\t331.8 ± 14.4\t1755\r\nHα
λ6564.60b,e\t274.1 ± 11.9\t1457\r\n[N ii] λ6585.27\t7.08 ± 0.91\t12.8\r\n[S ii]
λ6718.29\t0.68 ± 0.29\t4.78\r\n[S ii] λ6732.67\t0.81 ± 0.30\t4.74\r\nE(B − V)\t\t⋯\r\nFC
III]\t11.58 ± 0.49\t⋯\r\nb\t6.94 ± 0.15\t⋯\r\nNotes. Reddening-corrected emission-line
intensities of lines used in this analysis from the archival rest-UV and GLIMPSE
rest-optical JWST/NIRSpec spectra for RXCJ2248-ID3. Note that no scaling was performed
between the archival UV and GLIMPSE-D optical pointings (not needed for this work).
Thus, UV fluxes are given relative to the FC III]λλ1907,09 × 100 and optical fluxes
are given relative to FHβ × 100. The last three rows list the dust attenuation derived
using the J. A. Cardelli et al. (1989) reddening law and the rest-frame C iii] λλ1907,09
and Hβ flux in units of 10−18 erg s−1 cm−2. Additionally, the fluxes reported here
are for a single image of RXCJ2248 (ID3), whereas M. W. Topping et al. (2024) report
fluxes for coadded spectra of multiple images. aNote that N iii] λ1750 and [O ii]
λ3728 fluxes are the integrated values for the N iii] λλ1746,1748,1749,1752,1754
quintuplet and [O ii] λλ3727,3730 doublet, respectively. bEmission-line profile
was best fitted with a narrow Gaussian and two broad Gaussian components; only the
corrected narrow-line flux is listed here (see Section 2.2 and Figure 3). c[Ar iv]
λ4713+He iλ4714 is a blended line profile at the observed resolution. Thus, the
[Ar iv] λ4713 is determined by subtracting the He iλ4714 flux, which is predicted
from the He i λ4473 flux. dUncorrected for collisional excitation. eCorrected for
collisional excitation.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nThe
reddening due to dust, characterized by E(B − V), was determined by comparing the
observed Balmer decrements with the theoretical Balmer ratios assuming case B and
an extinction law, for which we tested the parameterization from both J. A. Cardelli
et al. (1989) and D. Calzetti et al. (2000). The E(B − V) value for a given Balmer
ratio was determined iteratively until convergence, recomputing the H i theoretical
ratio using the updated electron temperature from the reddening-corrected [O iii]
λ4364/λ5008 flux ratio and density from the reddening-corrected N iv] λ1483/λ1487
flux ratio in each iteration. In this way, the reddening, electron temperature,
and electron density were solved for simultaneously and consistently.\r\n\r\nA greater
enhancement of the observed FHα/FHβ decrement than of the FHβ/FHγ decrement can
arise under high-density conditions, where collisional excitation selectively enhances
the lowest excited level (n = 2; requires lowest energy to excite), leading to higher
Hα flux relative to Hβ and Hγ. To assess whether such an enhancement is physically
plausible, we examined the Cloudy photoionization models (M. Chatzikos et al. 2023;
C. M. Gunasekera et al. 2023) presented in Z. Martinez et al. (2025), which span
a wide range of nebular densities (up to ne = 109 cm−3). For the nebular conditions
determined in this work (i.e., Te, , Z, N/O; see Section 4), densities of ne ∼ 106
cm−3 are needed to produce the observed Hα enhancement while minimally affecting
Hβ and Hγ. Although this density is roughly an order of magnitude higher than the
values measured in M. W. Topping et al. (2024) and in this study (see Section 4.1
and Table 3), it could indicate that the interstellar medium (ISM) contains unresolved
clumps of even higher density than the volume-weighted values probed by the density
diagnostics used in this work. We, therefore, attribute the observed Hα excess to
collisional enhancement.\r\n\r\nTable 3. Nebular Conditions and Abundances for RXCJ2248-ID3\r\n\r\nProperty\tIon.
E\tUsed\tValue\r\n \t(eV)\t \t \r\nTemperatures:\t \t \r\nTe,high meas. (K)\t35.11–54.93\tne(N+3)\t1.97
± 0.03 × 104\r\nTe,int. used (K)\t23.33–34.83\tD. R. Garnett (1992)\t1.81 ± 0.02
× 104\r\nTe,low used (K)\t13.62–35.11\tD. R. Garnett (1992)\t1.68 ± 0.02 × 104\r\nDensities:\t
\t \t \r\nne(N+3) (cm−3)\t47.45–77.47\tTe,high\t\r\nne(Ar+3) (cm−3)\t40.74–59.81\tTe,high\t\r\nne(C+2)
(cm−3)\t24.38–47.89\tTe,int.\t\r\nne(Si+2) (cm−3)\t16.35–33.49\tTe,int.\t\r\nne(S+)
(cm−3)\t10.36–23.33\tTe,low\t\r\nO Abundances:\r\nO+/H+ (×10−5)\t13.62–35.11\tTe,low;
ne(Si+2)\t0.186 ± 0.148\r\nO+2/H+ (×10−5)\t35.11–54.93\tTe,high; ne(Ar+2)\t5.473
± 0.261\r\n \t \t7.753 ± 0.023\r\nIonization Parameters:\r\nlogUint.(O32)\t13.62–54.93\tne
= 104 cm−3\t−1.24 ± 0.23\r\nlogUhigh(N43)\t29.60–77.47\tne = 105 cm−3\t−0.69 ± 0.10\r\nN
Abundances:\r\nN+3/O+2\t47.45–77.47\tTe,high; ne(N+3)\t0.277 ± 0.043\r\nN+2/O+2\t29.60–47.45\tTe,high;
ne(C+2)\t0.145 ± 0.070\r\nN+/O+\t14.53–29.60\tTe,low; ne(Si+2)\t0.367 ± 0.259\r\nICF(N+3/O+2)\t47.45–77.47\tTe,high;
ne(N+3)\t1.542\r\nICF(N+2/O+2)\t29.60–47.45\tTe,high; ne(C+2)\t2.547\r\nICF(N+/O+)\t14.53–29.60\tTe,low;
ne(Si+2)\t0.814\r\nlog(N/O)\t⋯\t⋯\t−0.368 ± 0.062\r\nlog(N/O)\t⋯\t⋯\t−0.434 ± 0.071\r\nlog(N/O)\t⋯\t⋯\t−0.525
± 0.257\r\nlog(N/O)all\t⋯\t⋯\t−0.375 ± 0.056\r\n⋯\t⋯\t−0.390 ± 0.035\r\nC Abundance:\r\nC+2/O+2\t24.38–47.89\tTe,int;
ne(C+2)\t0.107 ± 0.014\r\nICF(C+2/O+2)\t24.38–47.89\tTe,int; ne(C+2)\t1.498\r\nlog(C/O)\t
\t \t−0.795 ± 0.052\r\nSi Abundance:\r\nSi+2/O+2\t16.35–33.49\tTe,low; ne(Si+2)\t0.005
± 0.001\r\nICF(Si+2/O+2)\t16.35–33.49\tTe,low; ne(Si+2)\t3.507\r\nlog(Si/O)\t⋯\t⋯\t−1.781
± 0.157\r\nNote. Ionic and total abundances for RXCJ2248-ID3. Column (1) lists the
property, while Column (2) lists the associated ionization potential energy range
(eV), Column (3) lists the temperature and/or density used in the calculation, and
Column (4) provides the final values. All calculations reported here only used the
narrow components when multicomponent fits were performed. Note that the temperatures
for the intermediate- and low-ionization zones were inferred from Te,high using
the Te–Te relationships of D. R. Garnett (1992). Two ionization parameters are reported
for the O32 and N43 indicators from Z. Martinez et al. (2025). The oxygen abundance
was determined using the archival [O ii] λ3728 detection and the new [O iii] λ5008
fit. N/O was determined using four different ion+ICF (from Z. Martinez et al. 2025)
combinations: (1) optical N+/O+; (2) UV N+2/O+2; (3) UV N+3/O+2; and (4) combination
(N++N+2+N+3)/(O++O+2). C/O and Si/O were determined from the archival UV emission
lines only.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nAccordingly,
we adopted the reddening derived from Hγ/Hβ, mag using J. A. Cardelli et al. (1989)
(the D. Calzetti et al. (2000) value is similar at E(B − V) = 0.050 ± 0.1215 mag),
and corrected all emission lines for the resulting (minimal) dust attenuation. We
used the D. Calzetti et al. (2000) reddening law for the rest-UV emission lines
(λ < 3200 Å) and the J. A. Cardelli et al. (1989) reddening law for the rest-optical
emission lines (λ > 3200 Å). After applying the reddening correction, the Hα/Hβ
ratio still shows a collisional excess of 0.204 above the theoretical value; we
correct for this excess and report a final FHα = 1.985 × 10−17 erg s−1 cm−2.\r\n\r\nThe
adopted reddening and dereddened line intensities are listed in Table 2 for all
line fluxes used in this work. Note that rest-UV and rest-optical lines should not
be compared or combined in line ratios. Since the rest-UV and rest-optical spectra
were obtained during different observing runs with distinct pointings and strategies,
we report the UV lines relative to FCIII]λλ1907,1909 × 100 and the optical lines
relative to FHβ × 100, without applying any relative scalings between the two datasets.\r\n\r\n3.
Wolf Rayet Stars at z = 6.1\r\nThe WR stage of massive star evolution is an important,
short-lived phase that can have significant effects on the chemical composition
of the local ISM. We provide a brief overview here (see, e.g., P. A. Crowther 2007,
for a more thorough review). WR stars are massive stars that have entered the core
He-burning phase and have lost their outer envelope either via strong stellar winds
or due to binarity effects (i.e., stripping via Roche Lobe overflow or mergers).
The first phase of WR stars occurs when the outer H layer has been ejected, revealing
the H core-burning products such that their spectra are characteristically He and
N rich but are H-poor. Such stars are known as nitrogen-type WR, or WN, stars, and
are often identified by strong N iii, N iv, and N v emission lines, especially the
broad optical “blue bump” near λ4650. The blue bump is a complex of features, including
N iii λλ4634,4642, C iii λ4649,4667, Fe iii λ4660, and He ii λ4687. Subsequently,
stars that are massive enough for core He-burning and for their winds to remove
their outer He envelope and expose the produced C enter the WR carbon (WC) phase.
WC stars also have strong, broad He ii emission and strong C and O emission, such
that they are identified by the optical WR C iv λλ5803,5814 doublet (the “red bump”).
As a result, the typically very strong winds of the WR phase can produce significant
N enrichment during the WN phase and drive strong C ejection during the WC phase.
After the WC phase, a WR-oxygen phase may ensue, but we forgo discussion of this
phase here.\r\n\r\nThe rest-frame UV and optical spectra shown in Figure 2 can be
used to characterize the WR nature of the stellar population in RXCJ2248-ID3. Both
the UV and optical He ii emission features are kinematically broadened compared
to the narrow nebular emission features in RXCJ2248-ID3, indicative of WR or VMS
winds. F. Martins et al. (2023, 2025) have shown that young star-forming regions
dominated by VMSs can be distinguished from WR stars using the morphology of the
blue and red bumps. In particular, VMSs produce blue bumps with He ii λ4687 emission
but little to no N iii emission and red bumps with narrow C iv λλ5803,5814 emission.
Thus, strong detections of N iii in the blue bump favor a WN interpretation (e.g.,
F. Martins et al. 2023; D. A. Berg et al. 2024; T. E. Rivera-Thorsen et al. 2024).\r\n\r\nThe
upper right-hand panel of Figure 2 highlights the blue bump spectral regime, showing
weak, broad He ii and N iii λ4642 in RXCJ2248-ID3, both of which are characteristic
of metal-poor WN stars. Just redward of the N iii λ4642 line in the blue bump (but
blueward of [Fe iii]), a second less prominent emission feature is seen, but it
is difficult to determine whether this is due to C iii or O ii emission, or both.
Furthermore, the red C iv bump is not detected, suggesting little to no contributions
from WC stars or VMSs in the spectrum. Thus, we only significantly detect the blue
WR bump, suggesting that WN stars are likely present.\r\n\r\n4. Nebular Properties\r\nUsing
the updated narrow-component emission-line fits presented in Section 2.2, we determined
the nebular properties of RXCJ2248-ID3. Following D. A. Berg et al. (2021), we adopt
the four-zone ionization model to account for the high-ionization emission observed.
In this model, the ionization potential energy ranges of N+, S+2, O+2, and He+2
define the low-, intermediate-, high-, and very high-ionization zones, respectively.
For all calculations, we use the PyNeb package in Python with the atomic data adopted
in D. A. Berg et al. (2019), which includes a six-level atom model for oxygen in
order to utilize the UV O iii] λ1666 line. Below, we determine temperatures and
densities, although Te(O+2) and ne(N+3) were codetermined during the iterative reddening
calculation (see Section 2.3) in Section 4.1, ionization parameters in Section 4.2,
and abundances in Section 4.3.\r\n\r\nWe note that the UV spectra do not have sufficient
S/N to decompose narrow and broad components following the same method as the optical
lines. As a result, density diagnostics and abundances determined from UV lines
may include contributions from multiple kinematic components, while optical temperatures,
densities, and abundances are derived from narrow components alone. If the broad
component arises from gas with distinct physical conditions, this could introduce
systematic offsets. For this reason, we examine the potential impact of UV broad
components in Section 4.4.\r\n\r\n4.1. Temperature and Density\r\nOne of the unique
characteristics of RXCJ2248-ID3 is its large number of density-sensitive emission-line
ratios. M. W. Topping et al. (2024) previously reported densities from the three
UV line ratios of Si iii] λ1883/λ1892, characterizing the intermediate-ionization
zone, C iii] λ1907/λ1909, characterizing the intermediate- to high-ionization zone,
and N iv] λ1483/λ1486, characterizing the high- to very high-ionization zone. The
new high-S/N optical spectra enables us to measure, for the first time, densities
from the low-ionization [S ii] λ6717/6731 ratio and the high- to very high-ionization
[Ar iv] λ4713/λ4741 ratio.\r\n\r\nWe use our narrow-component dereddened flux measurements
to compute densities for all five line ratios and the high-ionization zone temperature
from the [O iii] λ4364/λ5008 ratio. The high-ionization zones Te(O+2) and ne(N+3)
were simultaneously determined during the iterative reddening calculation in Section
2.3 to account for the sensitivities of both diagnostics. If the low density limit
was assumed instead (ne ≲ 102 cm−3), as is common practice at low-redshift, the
observed [O iii] λ4364/λ5008 flux ratio would lead to unphysical temperatures (i.e.,
above the limit set by H cooling of ∼2.5 × 104 K). Thus, a physical and robust solution
requires high densities to properly account for the reduced λ5008 flux due to collisional
de-excitation. Furthermore, Z. Martinez et al. (2025) recently showed that densities
derived from both optical and UV diagnostics underpredict the true volume-averaged
density in multiphase, high-density systems, with more severe underprediction from
the optical diagnostics. Therefore, it is necessary to use UV density diagnostics
in high-density environments, though the true density will still be underestimated
in multiphase gas (see, e.g., Figure 11 of Z. Martinez et al. 2025).\r\n\r\nFor
the high-ionization zone, we found a Te(O+2) = 1.97 ±0.03 × 104 K and ne(N+3) cm−3,
which is consistent with the density of ne(N+3) cm−3 reported by M. W. Topping et
al. (2024), but lower than their temperature of 2.46 ± 0.26 × 104 K due to our broad
component fits of both [O iii] λ4364 and λ5008. Adopting our Te(O+2) as the high-ionization
temperature (Te,high), we then applied the Te–Te relations of D. R. Garnett (1992)
to estimate the intermediate-ionization temperature (Te,int.) and low-ionization
temperature (Te,low).\r\n\r\nThe determined temperatures were used for the subsequent
density calculations in their respective ionization zones. Note that the [Ar iv]
λ4713 and He i λ4714 lines are blended in the G395M grating. Therefore, we corrected
the [Ar iv] λ4713 flux for the He i λ4714 contribution, predicting the He i λ4714
flux from the measured He i λ4473 flux and the theoretical He i λ4714/λ4473 ratio
(∼0.21 for the conditions in RXCJ2248-ID). The resulting densities, all of which
fall within their respective diagnostic ranges, and temperatures are reported in
Table 2.\r\n\r\nRemarkably, RXCJ2248-ID3 is one of few galaxies, and the only galaxy
yet at high redshifts, to have significant (>3σ) electron density measurements from
five different ions that span a large ionization range (∼10–77 eV). Furthermore,
the densities in RXCJ2248-ID3 appear to be organized into an interesting nebular
stratification. The UV emission lines trace the densest gas, with ne(N+3) = 2.65
× 105 cm−3 in the highest-ionization gas, followed by ne(C+2) = 7.94 × 104 cm−3
and ne(Si+2) = 4.77 × 104 cm−3. In contrast, the optical high-ionization lines are
emitted from regions of lower densities: the optical [Ar iv] diagnostic has an overlapping
ionization energy range with the UV N iv] diagnostic but a density that is an order
of magnitude lower.\r\n\r\nThere are two possible interpretations of the measured
array of densities. First, since the UV lines also have higher excitation energies,
they could originate preferentially from hotter, denser clumps. This would imply
a strongly inhomogeneous ISM, in which compact, high-pressure structures dominate
the UV line emission while somewhat more diffuse gas produces much of the optical
emission. Alternatively, the multiphase ISM may span a smaller dynamic range of
densities than we measure due to the suppression of the optical diagnostics. Z.
Martinez et al. (2025) showed that for an ISM with a mix of low- (e.g., 103 cm−3)
and high-density gas (e.g., 105 cm−3) that has a true volumetric density that is
somewhere in between, the low-ionization optical diagnostics will always be significantly
biased low, close to the low-density gas value, until the fraction of high-density
gas is very high (e.g., >95%). This effect occurs when ne-diagnostic line ratios
have low critical densities (e.g., ne,crit([S ii])≈2 × 103–5 × 103 cm−3), such that
emission from the high-density gas is collisionally suppressed beyond detection.
The magnitude of this effect decreases with increasing critical density such that
[S ii] is significantly affected, [Ar iv] is moderately affected (ne,crit ≈ 2 ×
104–2 × 105 cm−3), and the UV Si iii], C iii], and N iv] (ne,crit ≈ 5 × 104–5 ×
1010 cm−3) are minimally affected, albeit still biased low. In this scenario, there
would still be density stratification, but with smaller differences.\r\n\r\nAll
together, the nebular diagnostics in RXCJ2248-ID3 support a picture of a multiphase
nebula with density and temperature stratification, likely reflecting a clumpy ISM
shaped by the feedback and local radiation field variations of bursty star formation
(see, also, N. Choustikov et al. 2025; Y. Harikane et al. 2025b; M. Usui et al.
2025). This picture is also consistent with the density stratification that has
been reported for dwarf galaxies both near and far (e.g., B. L. James et al. 2016;
D. A. Berg et al. 2021; M. Mingozzi et al. 2022; X. Ji et al. 2024; M. W. Topping
et al. 2024), but with typical densities increasing with redshift (e.g., Y. Isobe
et al. 2023; Abdurro’uf et al. 2024; Z. Martinez et al. 2025; M. W. Topping et al.
2025a).\r\n\r\n4.2. Ionization Parameter\r\nThe ionization parameter of RXCJ2248-ID3,
, determined using the typical O32 = Iλ5008/Iλ3728 diagnostic is reported in M.
W. Topping et al. (2024) to be in the high range of to −1. We recompute the ionization
parameter for RXCJ2248-ID3 using the O32 and N43 = Iλλ1483,1486/Iλ1750 diagnostics
from Z. Martinez et al. (2025) that are calibrated for densities in the 102 ≤ ne(cm−3)
≤ 106 range. We estimate a using O32, which is consistent with the value reported
by M. W. Topping et al. (2024), and using N43. Note, however, that the O32 diagnostic
is very sensitive to the assumed density (Z. Martinez et al. 2025), making this
value highly uncertain in dense gas. For example, densities of ne = 103–105 cm−3
would lead to a range of to −2.04, respectively.\r\n\r\n4.3. Abundances\r\nHere,
we present direct-method abundances of oxygen-to-hydrogen (O/H) (Section 4.3.1),
N/O (Section 4.3.2), carbon-to-oxygen (C/O) (Section 4.3.3), and silicon-to-oxygen
(Si/O) (Section 4.3.4) for RXCJ2248-ID3 using narrow-line flux ratios and the measured
temperatures and densities presented in Section 4.1. Nearly all of the optical lines
used in this work have sufficient S/N to simultaneously constrain broad and narrow
emission components, but there are a few exceptions, all of which are low-ionization
lines. The [O ii] λ3728 line was not covered by the GLIMPSE-D spectrum and so lacks
the S/N to fit broad components. Both [N ii] λ6585 and [S ii] λλ6718,6733 are covered
in the high-S/N GLIMPSE-D spectrum but are either blended with stronger features
or too weak to fit broad components. On the other hand, the [O ii] and [S ii] lines
have low critical densities around ne,crit ∼ 103 cm−3 such that any moderate to
high-density broad components are likely collisionally de-excited away. Their narrow-component
fluxes could also be significantly reduced by collisional de-excitation; however,
the missing [O ii] emission is likely small in the absolute sense for such a high-ionization
object. Emission from [N ii] is less likely to be collisionally de-excited (ne,crit
∼ 105 cm−3), so a hidden broad component could lead to an overestimate of the N/O
abundance, but this effect would be somewhat countered by the underestimated [O
ii] flux. In the end, the consistency of N/O derived independently from UV and optical
tracers in Section 4.3.2 below suggests that these effects do not significantly
impact our results.\r\n\r\nTo calculate the total or relative abundance of an element,
we determine and sum the individual observed ions and then apply an ionization correction
factor to account for unseen prominent ionization states. The abundance of an individual
ionic species, Xi, relative to hydrogen is determined as\r\n\r\nwhere jλ(i) is the
emissivity determined for the appropriate ionization zone temperature and density.
Given the tendency of the optical density diagnostics to severely underestimate
the density in high-density environments, we instead adopt the UV-derived densities.
Note that the abundances presented below have not been corrected for the fraction
of atoms embedded in dust. However, the level of depletion onto dust grains is expected
to be small for the low metallicity of RXCJ2248-ID3 (e.g., A. Rémy-Ruyer et al.
2014; F. Galliano et al. 2018; J. Roman-Duval et al. 2022). Y. Isobe et al. (2026)
also infer negligible dust depletion for RXCJ2248-ID3 based on the high value of
Si/O that that they determine, but this is inconsistent with the value we determine
below. Details of elemental abundance determinations are given below.\r\n\r\n4.3.1.
Oxygen Abundance\r\nWe determine the total O/H abundance as the sum of the O+/H+
and O+2/H+ ionic abundances, determined from the [O ii] λ3728 and [O iii] λλ4960,5008
optical emission lines. We observe no strong O0 or O+3 emission, indicating that
contributions from other ions are negligible. The resulting ionic and total oxygen
abundances are presented in Table 2. Similar to M. J. Hayes et al. (2025) and Z.
Martinez et al. (2025), we find that one of the most significant effects of accounting
for high densities is the resulting decrease in electron temperature and subsequent
increase in oxygen abundance (see, also, H. Katz et al. 2023). In our work, this
results both from accounting for the missing [O iii] λ5008 flux due to collisional
de-excitation and from correcting the narrow emission for broad emission components
at their base. M. W. Topping et al. (2024) also incorporated the high densities
seen in RXCJ2248-ID3 but did not have the S/N to fit the broad emission components
in both [O iii] λ5008 and λ4364. As a result, we measure an oxygen abundance of
. Note that if unresolved high-density clumps (ne ≳ 105 cm−3) are present (as suggested
in, e.g., Section 2.3), it could introduce additional uncertainty by biasing the
luminosity-weighted [O iii] λ4364/λ5008 ratio to higher densities, which would drive
the derived Te higher and O/H abundance lower. However, Z. Martinez et al. (2025,
see Figure 11), showed that the use of high-critical density UV density diagnostics
largely mitigate this effect in a density stratified medium.\r\n\r\n4.3.2. Relative
N/O Abundance\r\nThe extraordinary simultaneous detections of [N ii] λ6585, N iii]
λ1750, and N iv] λλ1483,1487 enable multiple determinations of the N/O abundance.
Therefore, we calculate N/O abundances using four different ionic methods\r\n\r\n\r\n\r\n\r\nwhere
[O ii] λ3728 is used for the N+/O+ determination, O iii] λ1666 is used for the N+2/O+2
and N+3/O+2 calculations, and X(N+i) and X(O+i) are the N and O ionization fractions,
respectively. We use the density-dependent ICFs from Z. Martinez et al. (2025),
who provide prescriptions for densities of ne = 102, 103, 104, 105, and 106 cm−3.
We, therefore, round our density measurements to the nearest order of magnitude
and use the intermediate-ionization for the N+/O+ ICF and the high-ionization for
the N+2/O+2 and N+3/O+2 ICFs. The resulting N ICFs and N/O abundances are reported
in Table 3.\r\n\r\nThe four N/O determinations of RXCJ2248-ID3 are in close agreement,
far above the expected value for its metallicity. Visually, this is shown in the
upper left-hand panel of Figure 4, which plots the relative N/O versus O/H abundance
with RXCJ2248-ID3 marked by purple diamonds. The traditional N/O–O/H trend has been
established by many z ∼ 0 studies of H ii regions and galaxies (gray points: C.
Esteban et al. 2002, 2009, 2014; L. S. Pilyugin & T. X. Thuan 2005; L. van Zee &
M. Haynes 2006; J. García-Rojas & C. Esteban 2007; Á. R. López-Sánchez et al. 2007;
D. A. Berg et al. 2012, 2016,2019, 2020). The empirical trend is a bimodal relationship,
with a flat trend due to primary (or metallicity-independent) N production at low
metallicities () and an increasing N/O trend with O/H as secondary (or metallicity-dependent)
N production becomes increasingly important at higher metallicities (). As a visual
guide, the primary N/O plateau from D. A. Berg et al. (2019, dashed purple line)
is shown and the empirical stellar curve from D. C. Nicholls et al. (2017, solid
green line) is shown as an example of the full primary and secondary curve.\r\n\r\nZoom
InZoom OutReset image size\r\nFigure 4. Relative C and N abundance trends versus
metallicity. Nitrogen to oxygen ratio versus oxygen abundance for star-forming galaxies
is plotted in the left panels, while C/O ratio versus oxygen abundance is plotted
in the middle panels, and carbon to nitrogen abundance versus oxygen abundance is
plotted in the right panels. Top row: RXCJ2248-ID3 is shown relative to the observed
z ∼ 0 trend and other high-z galaxies. The abundances for RXCJ2248-ID3 are shown
as purple diamonds, where multiple N/O points show the measurements for each ionic
N/O calculation method. For comparison, we also plot the abundances derived for
RXCJ2248-ID3 by M. W. Topping et al. (2024) as turquoise squares. The typical bimodal
N/O trend is characterized by local dwarf (gray diamonds; L. van Zee & M. Haynes
2006; D. A. Berg et al. 2012, 2016, 2019) and spiral galaxy (gray circles; C. Esteban
et al. 2002, 2009, 2014; L. S. Pilyugin & T. X. Thuan 2005; J. García-Rojas & C.
Esteban 2007; Á. R. López-Sánchez et al. 2007; D. A. Berg et al. 2020) H ii region
measurements. The primary N/O plateau from D. A. Berg et al. (2019) is shown as
a dashed purple line, while the solid green line is the empirical stellar curve
from D. C. Nicholls et al. (2017). Additional C/O literature measurements for dwarf
galaxies are from M. A. Peña-Guerrero et al. (2017) and P. Senchyna et al. (2017).
Abundances for z > 2 galaxies from Z. Martinez et al. (2025) are plotted as blue
plus signs for galaxies with UV N+2/O+2 derived abundances and pentagons for optical
N+/O+ derived abundances. Bottom row: The same observed samples are shown as the
top row, but with the z ∼ 0 sample represented by the shaded gray regions. The observed
abundances of RXCJ2248-ID3 are compared to updated dual-burst chemical evolution
models of C. Kobayashi & A. Ferrara (2024, string of circles), color coded by age
since onset of the second burst. The models have been modified to reproduce both
the enhanced N/O and relatively deficient C/O observed for RXCJ2248-ID3, which requires
enrichment from WN but very little WC enrichment, as expected at low metallicities.\r\n\r\nDownload
figure:\r\n\r\nStandard imageHigh-resolution image\r\nFor comparison, we plot the
high-quality high-redshift N/O measurements that were calculated in a consistent
manner as the present work (with direct-method Te and ne determinations and ne-dependent
ICFs) by Z. Martinez et al. (2025). N/O abundances determined using N+2/O+2 are
plotted as blue + symbols, while N+/O+ determinations are plotted as blue pentagons.
Of these galaxies, the closest comparison to RXCJ2248-ID3 is CEERS-1019 (see, also,
R. Marques-Chaves et al. 2024), while only GDS 3073 and GN-z11 have higher relative
N/O abundances and only GDS 3073 is more enhanced in N/O for its O/H abundance.\r\n\r\nWe
find that all four ionic methods produce consistently high N/O values within their
uncertainties, with a weighted mean of . This is an important result because RXCJ2248-ID3
is the first galaxy to have consistently enhanced N/O abundances measured from both
the rest-frame UV high-ionization and the optical low-ionization emission lines.
Furthermore, measuring consistent N/O values from three different ionic methods
strengthens our confidence in the robustness of the N/O measurement, although uniform
N/O across the ionization structure of the nebula is not a given in a stratified
medium. While there is strong evidence for a stratified, or perhaps very clumpy,
density structure in RXCJ2248-ID, the N/O abundance appears to be well mixed.\r\n\r\n4.3.3.
Relative C/O Abundance\r\nMeasuring the C/O abundance provides a crucial comparative
baseline for interpreting the origin of elevated N/O in RXCJ2248-ID3. Similar to
N, C has a pseudosecondary17 production pathway, but the dominant nucleosynthetic
sources and timescales differ for C and N. Briefly, both C and O are primarily produced
in massive stars (>8 M⊙) on relatively short timescales such that the C/O ratio
is a relatively stable tracer of massive star yields, although some C is produced
via low- to intermediate-mass AGB stars (∼1.5–3 M⊙). In contrast, some N is produced
by massive stars (e.g., through rotational mixing and WR winds) but most N comes
from intermediate-mass AGB stars (∼4–8 M⊙), which release N on longer timescales
(∼200 Myr). Therefore, N/O and C/O together serve as diagnostics of the recent star
formation history, constraining the recent enrichment mechanisms of galaxies (e.g.,
D. R. Garnett 1990; R. B. C. Henry et al. 2000; C. Chiappini et al. 2003; E. Pérez-Montero
& T. Contini 2009; D. A. Berg et al. 2019; E. Pérez-Montero et al. 2021).\r\n\r\nRelative
C/O abundances are typically determined using the C iii] λλ1907,1909/O iii] λ1666
ratio to calculate C+2/O+2 and assuming that C/O ≈ C+2/O+2. This method is sometimes
used alone owing to the fact that (1) C+2 and O+2 have somewhat similar ionization
potentials (24.38 and 35.12 eV, respectively), (2) the upper levels of the λ1666
and λλ1907,1909 transitions have similar excitation potentials (∼6.5 and ∼7.5 eV,
respectively), and (3) the integrated fluxes of λ1666 and λλ1907,1909 are not sensitive
to collisional de-excitation for the densities measured here. However, for the high-ionization
nebulae in RXCJ2248-ID3, it is important to account for contributions from the C+3
species and any unseen species. We note that the C iv λλ1548,1550 doublet is clearly
observed in the rest-UV spectrum of RXCJ2248-ID3, but these lines are resonant and
can be affected by the C iv stellar wind feature and ISM absorption, and so determining
the intrinsic flux and subsequent C+3 abundance is challenging. Instead, we use
an ICF determined from the photoionization models presented in Z. Martinez et al.
(2025) such that\r\n\r\nWe used the and a density of ne(C+2) ∼ 105 cm−3 to determine
the C ICF. The resulting C ICF and C/O abundance are reported in Table 3.\r\n\r\nThe
C/O and C/N abundances for RXCJ2248-ID3 are plotted in the upper middle and right-hand
panels of Figure 4. Empirical trends of C/N at z ∼ 0 are found to be flat, albeit
with significant scatter (see shading in Figure 4), suggesting that the dominant
nucleosynthetic mechanisms of C are similar to those of N (e.g., D. R. Garnett et
al. 1999; C. Esteban et al. 2014; D. A. Berg et al. 2016, 2019). However, while
the production of both C and N appear to be metallicity-dependent, the scatter in
their trend is consistent with differing production timescales due to stars of different
masses. Thus, the variations observed in CNO abundance patterns of high-redshift
galaxies may be the result of taking a snapshot of many galaxies at different times
since their most recent onset of star formation.\r\n\r\nRXCJ2248-ID3 appears to
have a similar CNO abundance pattern to other high-redshift N emitters, characterized
by enhanced N/O but relatively deficient C/O such that their C/N is very deficient
compared to the expectations from low-redshift trends. This suggests that these
high-redshift N-emitting galaxies are enhanced in N relative to both O and C. If
massive stars in the WN phase are present, they will have recently produced 14N
at the expense of 12C through the CNO cycle, meaning C used as a catalyst in the
cycle initiation will have been consumed as N is removed during the bottleneck step
via dredged up, preventing the return of C at cycle completion. Thus, C/N-deficiency
is consistent with a recent, intense episode of N enrichment and C consumption from
WN stars. Conversely, if both N/O and C/O were elevated in tandem, it could point
to broader enrichment by massive stars, such as enrichment from both WN and WC stars,
whose contributions increase at higher metallicities.\r\n\r\n4.3.4. Relative Si/O
Abundance\r\nDetecting Si iii] λλ1883,1892 in RXCJ2248-ID3 enables the rare opportunity
to measure the silicon-to-oxygen (Si/O) abundance in a z > 5 galaxy (see, also,
Y. Isobe et al. 2026, for Si/O in GN-z11). Silicon abundances are important for
multiple reasons. Silicon is highly refractory, making the Si/O ratio a sensitive
probe of dust depletion. Additionally, Si probes different channels of chemical
enrichment than CNO elements, as it is primarily an α-element produced by CCSNe,
but Type Ia SNe, AGB stars, and even pair-instability SNe are all expected to contribute
to the total Si abundance. For RXCJ2248-ID3 we determine the Si/O abundance using
the observed Si iii] λλ1883,1892/O iii] λ1666 ratio to calculate Si+2/O+2. Because
Si+2 and O+2 have rather different ionization potentials (16.3 eV versus 35.1 eV,
respectively), a Si ICF is required to convert Si+2/O+2 to total Si/O via\r\n\r\nSi
ICFs have been reported previously (e.g., D. R. Garnett et al. 1995), but none account
for the high-density conditions observed in RXCJ2248-ID3. Therefore, we determined
a Si ICF = 3.507 using the photoionization models presented in Z. Martinez et al.
(2025) using the and a density of ne(Si+2) ∼ 104 cm−3. Reported in Table 3, the
resulting (Si/O) = −1.781 ± 0.157 abundance is typical of metal-poor dwarf galaxies
(e.g., D. R. Garnett et al. 1995; Y. I. Izotov & T. X. Thuan 1999), consistent with
normal massive star production and low dust depletion.\r\n\r\n4.4. Potential Impact
of UV Broad Components\r\nThe exceptionally high S/N of the rest-optical GLIMPSE-D
spectrum allows for broad emission component fits that the rest-UV spectrum does
not. In Section 2.2, we found the broad emission component contribution to the narrow
[O iii] λ5008 flux to be 10.8%. To examine the possible effects such contamination
has on calculations of nebular conditions and abundances, we adopt 10.8% as the
contamination upper limit to the UV emission lines. We first consider the impact
on the UV density determinations, where we allow the broad components of the UV
density-sensitive emission-line ratios to have densities ranging from 102–106 cm−3.
After subtracting the potential broad component contribution, the revised densities
change up to Δne(Si+2), Δne(C+2), and Δne(N+3) over the range of broad component
densities considered. These values are within the reported uncertainties in Table
3, with the exception of the ∼1.2σ deviation for Δne of C+2.\r\n\r\nNext, we tested
the subsequent impact of UV densities that have been revised for possible broad
components on the properties determined from rest-optical emission lines: Te(O+2),
O/H, and N/O. For the range of Δne(N+3) above, the resulting K, which is within
1σ–2σ of the reported value in Table 3. Similarly, the impact of the revised densities
and temperatures on the oxygen abundance, dex, is also within 1σ–2σ. The impact
is even smaller for the nitrogen abundance, with dex being much smaller than the
N/O uncertainty.\r\n\r\nRelative UV abundances are impacted by changes in both the
nebular conditions and the relevant abundance emission-line ratio. However, the
resulting abundance deviations are small and within the original uncertainties:
dex, dex, and dex. Thus, we conclude that while considering the impacts of hidden
broad component contributions to the measured UV fluxes is important, the potential
biases do not affect the main results or conclusions of this work.\r\n\r\n5. A Short
Window of Intense WR Nitrogen Enrichment\r\nWe have presented evidence for WN stars
in RXCJ2248-ID3 in two forms: first, the rest-frame optical WR blue bump discussed
in Section 3 and shown in Figure 2; and second, a qualitative comparison of the
CNO abundances to patterns expected for WR stars in Section 4.3 and Figure 4. Below,
we examine the plausibility and impact of these WN stars by comparing RXCJ2248-ID3
to expected trends for WR stars with metallicity (Section 5.1), testing whether
stellar yields can reproduce the observed CNO abundance pattern (Section 5.2) and
assessing whether RXCJ2248-ID3’s stellar population can produce its inferred mass
of ionized N (Section 5.3). Together, these lines of investigation suggest that
the enhanced N/O and suppressed C/O in RXCJ2248-ID3 represent a short-lived enrichment
phase, unique to metal-poor, highly star-forming galaxies in the early Universe
(Section 5.4).\r\n\r\n5.1. WN Stars: The Dominant WR Phase at Low Metallicity\r\nTo
date, no individual resolved WR stars have been directly observed at metallicities
as low as RXCJ2248-ID3 (Z ∼ 0.1Z⊙). This is due, in part, to the lack of sufficiently
close (D ≲ 1 Mpc for the young, crowded clusters hosting WR stars), metal-poor,
star-forming galaxies (see C. Kehrig et al. 2013 for the closest metal-poor WR galaxy),
but a scarcity of WR stars in metal-poor environments is also expected because mass
loss through stellar winds scales with metallicity. We show the trend of the number
of WC/WN stars as a function of metallicity in Figure 5. The observed number of
WC/WN stars in M31 (∼175% Z⊙), the Milky Way (MW; Z⊙), M33 (∼40%–110% Z⊙), the Large
Magellanic Cloud (LMC; ∼40% Z⊙), and the Small Magellanic Cloud (SMC; ∼20% Z⊙) suggest
that the number of the WN/WC number ratio increases with decreasing metallicity
(e.g., G. Meynet & A. Maeder 2005; P. A. Crowther 2007; P. Massey et al. 2015; K.
Neugent & P. Massey 2019). This is because weaker metal line-driven winds, rotation,
or binary effects in metal-poor stars may be able to expose their nitrogen-rich
layers and initiate the WN phase but be insufficient to strip the stellar He atmosphere
and reveal the carbon-rich core to initiate the WC phase. Thus, if WR stars form
at Z ∼ 10% Z⊙, they are expected to be overwhelmingly WN-type. Additionally, A.
A. C. Sander et al. (2026) recently discovered a new class of WN–WO stars that point
to a low-metallicity WR evolutionary channel in which stars pass directly from the
WN to WO phase, potentially explaining spectra that show evidence for WN-like enrichment
and hard ionizing radiation without clear WC signatures.\r\n\r\nZoom InZoom OutReset
image size\r\nFigure 5. Observed and theoretical ratios of WC/WN star numbers as
a function of metallicity. Observed values for the SMC, LMC, MW, and M31 were compiled
by K. Neugent & P. Massey (2019), while newer values for M33 come from K. F. Neugent
& P. Massey (2023). For comparison, we also plot the trend presented in P. Massey
et al. (2017) for BPASS v2.0 binary stellar population synthesis burst models for
12+log(O/H) > 8 (solid line green line), which we extrapolate to lower metallicities
(dashed line). Enrichment from WR stars was used to explain the CNO abundances in
GN-z11 by C. Kobayashi & A. Ferrara (2024). We note the metallicity for GN-z11 determined
by Z. Martinez et al. (2025) is consistent with a WC/WN ratio of ∼0.1–0.2 and the
metallicity for RXCJ2248-ID3 from the current work, which predicts a much lower
WC/WN ratio of ∼0.03–0.10. Therefore, very little carbon enrichment from WC stars
is expected for RXCJ2248-ID3.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution
image\r\nThe spectral features of RXCJ2248-ID3 support the picture of WN star feedback
at low metallicity. As shown in Figure 2, the He ii emission is moderately broadened,
the N iii λ4642 line in the blue bump is prominent, and there is no evidence for
the red bump C iv feature, all consistent with the presence of WN stars at low metallicity.
The weakness of the He ii emission in terms of both flux and velocity width is expected
for the low-metallicity environment of RXCJ2248-ID3 (∼10% Z⊙) due to reduced wind
velocities and mass-loss rates (e.g., A. A. C. Sander et al. 2020). Similarly weak
WN features have also been reported in the nearby metal-poor galaxy SBS 0335-052
(Y. I. Izotov et al. 2006) and, at cosmic noon, the z ∼ 2.37 lensed galaxy the Sunburst
Arc (T. E. Rivera-Thorsen et al. 2024) and the z ∼ 2.22 M4327 galaxy (M. Curti et
al. 2025b).\r\n\r\nWe plot the WR blue bump profile of RXCJ2248-ID3 relative to
the Sunburst Arc and M4327 in Figure 6. For ease of comparison, we convolve the
Sunburst Arc R ∼ 2700 JWST/NIRSpec G140H spectrum to the R ∼ 1000 resolution of
the RXCJ2248-ID3 spectrum. For M4327, we retrieved the G140M spectrum obtained as
part of the Measuring Abundance at High Redshift with the Te Approach Survey (MARTA;
E. Cataldi et al. 2025) from the Dawn JWST Archive (DJA; K. E. Heintz et al. 2024;
A. de Graaff et al. 2025). Both the Sunburst Arc and M4327 spectra were scaled to
similar He ii strengths as RXCJ2248-ID3. These spectra immediately reveal similar
profiles, but with three distinct differences: (1) RXCJ2248-ID3 exhibits higher
gas ionization, as evidenced by the strong [Ar iv] λλ4713,4741 emission; (2) the
He ii stellar wind feature is significantly broader in both the Sunburst Arc (FWHM
= 1370 km s−1) and M4327 (FWHM = 1460 km s−1) than RXCJ2248-ID3 (FWHM = 530 km s−1),
consistent with stronger stellar winds at the higher metallicities of the Sunburst
Arc: (or Z ∼ 0.7 Z⊙; Z. Martinez et al. 2025) and M4327: (or Z ∼ 0.3 Z⊙; M. Curti
et al. 2025b); and (3) the WR N iii λ4642 line is much stronger in RXCJ2248-ID3,
which lacks WR C iv λλ5803,5814 emission, while the Sunburst Arc and M4327 exhibit
both N iii and C iv emission. These differences support a scenario in which the
z ∼ 2 WR galaxies hosts both WC and WN stars, but the more metal-poor RXCJ2248-ID3
hosts a young population of WN stars with no or very little WC contribution.\r\n\r\nZoom
InZoom OutReset image size\r\nFigure 6. The blue WR region of the optical spectrum
of RXCJ2248-ID3 (purple) is shown in comparison to the z ∼ 2.37 Sunburst Arc spectrum
from T. E. Rivera-Thorsen et al. (2024, blue), which has been convolved to R ∼ 1000
to match RXCJ2248-ID3, and the z = 2.22 M4327 spectrum obtained from the DJA, but
originally presented in M. Curti et al. (2025b, turquoise). All three galaxies show
characteristic signs of hosting WN stars but RXCJ2248-ID3 shows striking N iii λ4642
emission that is much stronger than both the Sunburst Arc and M4327. On the other
hand, the Sunburst Arc and M4327 show broader He ii emission, which is expected
for more metal-rich galaxies as stellar winds scale with metallicity.\r\n\r\nDownload
figure:\r\n\r\nStandard imageHigh-resolution image\r\n5.2. Relative Chemical Enrichment
from WN Stars\r\nWith the highest redshift detection of WN stars to date, we now
explore their chemical yields as a source of the abundance pattern in RXCJ2248-ID3.
C. Charbonnel et al. (2023) performed a comparable analysis for the extreme N/O
ratio observed in GN-z11 and found that such rapid nitrogen enrichment could arise
from normal massive stars with M⋆ ∼ 20–120 M⊙ or from supermassive stars (M⋆ ≳ 1000
M⊙) in protoglobular cluster environments. Their results and those of R. Marques-Chaves
et al. (2024) further demonstrated that the short-lived WN-like phase can produce
large N/O ratios within a few megayears of the burst, consistent with the timescales
inferred here, but that the observed C/O ratios are only compatible over a very
short time interval. Building on this theoretical groundwork, C. Kobayashi & A.
Ferrara (2024) showed that a dual-burst chemical evolution model with a short WR-dominated
enrichment phase could also match GN-z11’s enrichment pattern. Similarly, R. Marques-Chaves
et al. (2024) used N yields from rotating massive stars to demonstrate that a young,
WR-dominated stellar population could reproduce the observed CNO enrichment pattern
in CEERS-1019.\r\n\r\nThe models above provide a valuable physical framework for
linking stellar yields to galaxy-scale abundance evolution at early times. To extend
the methodologies outlined by these works to RXCJ2248-ID3, we first examine the
dual-burst chemical evolution model of C. Kobayashi & A. Ferrara (2024), which was
fine-tuned to reproduce the enhanced N/O in GN-z11 (reported by R. Maiolino et al.
2024). This model invokes two bursts of star formation, where the second triggers
a narrow (≲1 Myr) phase of WR-dominated enrichment. While the model can easily reach
the N/O enrichment level of RXCJ2248-ID3, it was also designed to yield the higher
O/H and C/O abundances observed in GN-z11 than in RXCJ2248-ID3, which was achieved,
in part, by enrichment from WC stars. The updated O/H abundance for GN-z11 determined
by Z. Martinez et al. (2025) makes it consistent with some carbon enrichment from
WC stars, as shown in Figure 5. However, with a metallicity of only Z ∼ 0.10 Z⊙,
the WR population in RXCJ2248-ID3 is expected to consist of few WC stars, and so
an updated chemical evolution model is needed to match its unique CNO abundance
pattern.\r\n\r\nWe modify the C. Kobayashi & A. Ferrara (2024) dual-burst model
to be more appropriate for the metal-poor conditions in RXCJ2248-ID3. In particular,
the galactic chemical evolution (GCE) model uses the same star formation history
and the standard IMF (for 0.01–120 M⊙) as in the fiducial model in C. Kobayashi
& A. Ferrara (2024) but reduces the contribution from WC stars. C/O ratios of the
nucleosynthesis yields vary depending on the uncertain nuclear reaction rates (e.g.,
12C(α, γ)16O) and the treatment of convection and mass loss (C. Kobayashi et al.
2006). In the updated model, 12C and 16O yields are taken from C. Kobayashi et al.
(2020) for all mass ranges of stars but the contributions from the WC wind phase
is scaled to ∼15% in order to match the empirical trends and theoretical expectations
that most massive stars will have insufficient winds to remove their He envelopes
at such low metallicities.\r\n\r\nWe plot the updated metal-poor dual-burst model
in the bottom row of Figure 4 as a time-series of points that are color coded by
the age since the onset of the second burst. In this model, the observed N/O, O/H,
and C/O abundances of RXCJ2248-ID3 are reached simultaneously ∼4.2 Myr after the
onset of the second burst. This young age is consistent with enrichment from WN
stars and with the derived clump age of Myr (A. Claeyssens 2025). Thus, the N/O-enhanced
and relatively C/O-deficient conditions in RXCJ2248-ID3 are produced by a short-lived
evolutionary phase following intense, bursty star formation.\r\n\r\nWe note that
the duration and impact of the WN phase may be significantly extended if the stars
evolve in binary systems. In the M. Limongi & A. Chieffi (2018) single-star models,
the WN phase typically lasts ∼0.03–0.3 Myr and, due to the metallicity-dependent
winds, require high initial masses (∼40 M⊙) to expose the He- and N-rich layers.
However, in close binaries, envelope stripping via mass transfer or common-envelope
evolution can induce WR phases in lower-mass stars (20–30 M⊙), largely independent
of the stellar metallicity. This channel can significantly prolong the WN lifetime
(up to ∼1 Myr) depending on the binary mass ratio and separation (e.g., J. J. Eldridge
et al. 2017; Y. Götberg et al. 2019; D. R. Aguilera-Dena et al. 2022). As a result,
binary evolution may enhance both the frequency and duration of the chemically selective
N/O enrichment phase, such as that observed in RXCJ2248-ID. On the other hand, L.
Boco et al. (2025) successfully modeled observations of single WR stars in the SMC,
suggesting that binary stripping may not be required to produce WR stars at low
metallicity. Clearly, the frequency, lifetimes, and formation channels of WR stars
in low-metallicity environments are not yet well understood. Future work incorporating
current binary and single star WR pathways into chemical evolution models may, therefore,
be essential for capturing the full range of nitrogen feedback in low-metallicity
starbursts at high redshift.\r\n\r\nTaken together, the massive star enrichment
scenario presented here, and explored in C. Charbonnel et al. (2023), R. Marques-Chaves
et al. (2024), and C. Kobayashi & A. Ferrara (2024), demonstrates that selective
enrichment of nitrogen by WN-dominated feedback can naturally reproduce the observed
CNO abundance pattern in compact, low-metallicity starbursts such as RXCJ2248-ID3.
We can now paint a full picture of the ISM in RXCJ2248-ID3. The consistency of N/O
across ions spanning a wide range of ionization potentials suggests that the WN-enriched
material has been efficiently mixed throughout the ionized gas. This apparent chemical
homogeneity does not contradict the strong density and temperature stratification
inferred from our diagnostics: a clumpy or multiphase ISM can remain compositionally
uniform if the enriched ejecta are well dispersed. Given the extreme compactness
of RXCJ2248-ID3 (Re ≈ 20 pc), the characteristic dynamical and sound-crossing times
are only a few ×105 yr, comparable to or shorter than the duration of the WN phase
itself. Under such conditions, turbulent and radiative mixing can rapidly homogenize
the heavy-element yields, producing a chemically uniform yet physically structured
nebula.\r\n\r\n5.3. The N Mass Budget\r\nA crucial point of validation is whether
an intense burst of star formation so early in the Universe could have produced
the amount of N present in RXCJ2248-ID3. Similar to the analysis in R. Marques-Chaves
et al. (2024), we test this by first estimating the ionized nitrogen mass using\r\n\r\nwhere
the atomic mass ratio is mN/mH = 14 and N/H is the nitrogen abundance of the ionized
gas. The hydrogen gas mass MH is derived from the Hα luminosity as\r\n\r\nwhere
mH = 1.67 × 10−27 kg, h = 6.626 × 10−27 erg s−1, νHα is the frequency of the Hα
emission line, and cm3 s−1 is the Case B effective recombination coefficient for
Hα assuming a Te = 1.97 × 104 K. We estimate the Hα luminosity using a luminosity
distance of dL(z = 6.1025) =1.817 × 1029 cm, the collision-corrected narrow-component
Hα flux, and a magnification of μ = 6.8877 (L. Furtak et al. 2025) to be LHα = 1.20
× 1042 erg s−1. Combining this LHα with the equivalent width (EW)(Hα) = 1457 Å,
we derive the star formation rate (SFR) using the simulation-based SFR(Hα) calibration
from I. G. Kramarenko et al. (2026). This method was developed to be more appropriate
for the bursty conditions at high redshift than traditional calibrations and gives
SFR = 3.2 M⊙ yr−1, similar to the SED-derived SFRs assuming a constant SFH for 1
Myr () and 10 Myr (; see Table 1). Adopting a filling factor of ε = 0.01-0.10, assuming
a compact starburst (e.g., R. C. Kennicutt 1984; G. Stasińska & D. Schaerer 1997),
a density of 104 cm−3, and the measured N/H value, we calculate the ionized nitrogen
mass to be .\r\n\r\nWe then compute the total nitrogen mass that can be produced
by the recent burst of star formation using the integrated nitrogen yield produced
by the modified C. Kobayashi & A. Ferrara (2024) model for the SED-derived stellar
mass of assuming a continuous SFH over the duration of the second burst (∼4.2 Myr).
This results in a total N mass of 435 M⊙, implying that ∼% of the gas is retained
from the WN winds and ionized when matched to the expected ionized N mass (∼) from
the crudely calculated observed value. Thus, WN stars formed in a recent burst within
a compact, high-density, and very clumpy/inhomogeneous (low-filling-factor) environment
can plausibly explain the N mass in RXCJ2248-ID3, even at low metallicity (∼10%
Z⊙), without invoking a top-heavy IMF or exotic enrichment channels.\r\n\r\n5.4.
The Ephemeral Imprint of WN Star on High−z Galaxies\r\nThe prominence of N/O enhancement
at z ≳ 5 but relative rarity in local star-forming galaxies likely reflects a combination
of environmental conditions and evolutionary factors that are unique to the early
Universe. To examine the likely environments, we plot the SFR surface density (ΣSFR)
versus EW of Hβ in Figure 7 for both z ≳ 6 N emitters (RXCJ2248-ID3: M. W. Topping
et al. 2024, this work; GNz9p4: D. Schaerer et al. 2024; GN-z11, EW(Hβ) inferred
from Hγ: A. J. Bunker et al. 2023; S. Tacchella et al. 2023; GDS 3073: E. Vanzella
et al. 2010; H. Übler et al. 2023; X. Ji et al. 2024; CEERS-1019: R. L. Larson et
al. 2023; R. Marques-Chaves et al. 2024; A1703-zd6: M. W. Topping et al. 2025b)
and local star-forming galaxies with enhanced SFRs from the COS Legacy Archive Spectroscopic
SurveY (CLASSY; B. L. James et al. 2021; D. A. Berg et al. 2022; N/O from K. Z.
Arellano-Córdova et al. 2025). The high-redshift galaxies, such as RXCJ2248-ID3,
exhibit compact morphologies (Re ≲ 102 pc) that lead to much higher SFR surface
densities than seen at z ∼ 0, as well as bursty star formation histories that favor
the rapid buildup of massive stars capable of entering the short-lived WN phases
(M⋆ > 20 M⊙). The high-redshift N emitters also have high Hβ EWs (>200 Å) that are
indicative of young current bursts of star formation (<5 Myr). This suggests that
compactness alone is not enough to observe enhanced N/O; we must also observe these
galaxies at the fleeting moments of very young bursts when WR stars are most active.\r\n\r\nZoom
InZoom OutReset image size\r\nFigure 7. SFR surface density versus Hβ EW for high-redshift
(z > 5) N emitters versus z ∼ 0 galaxies from the CLASSY survey (SFR: D. A. Berg
et al. 2022; N/O: K. Z. Arellano-Córdova et al. 2025), which have enhanced SFRs
similar to z ∼ 2–3 galaxies. High-redshift N emitters are only observed at young
ages (≲5 Myr), as indicated by the high Hβ EWs (EW> 200 Å), and in compact, dense
environments (ΣSFR > 10 M⊙ yr−1 kpc−1). Note that RXCJ2248-ID3 is plotted here using
the properties derived from M. W. Topping et al. (2024) for continuous star formation
to be consistent with the other N-emitter measurements.\r\n\r\nDownload figure:\r\n\r\nStandard
imageHigh-resolution image\r\nFigure 7 suggests a scenario of elevated N/O at low
metallicity being preferentially seen in galaxies with high SFR surface densities
and young stellar ages (e.g., D. Schaerer et al. 2024; M. W. Topping et al. 2024;
Z. Martinez et al. 2025). R. Marques-Chaves et al. (2024) also suggest that the
elevated N/O and high-ionization spectrum of CEERS-1019 trace a short evolutionary
window of a ≲5 Myr burst dominated by WN-like feedback. Furthermore, the theoretical
models of C. Charbonnel et al. (2023) predict that such phases are characteristic
of young, dense stellar systems, potentially analogous to protoglobular clusters,
reinforcing that our observed WN-driven enrichment is a natural outcome of clustered,
bursty star formation at early times.\r\n\r\nAt low metallicity, weaker stellar
winds require higher initial masses for stars to reach the WR phase, so a larger
total stellar mass must form in a burst to produce a detectable population of WN
stars. In compact galaxies beyond cosmic noon, this condition is naturally met in
systems with high SFR surface densities, which statistically sample the upper IMF
more fully and produce a detectable population of WN stars (e.g., J. Brinchmann
et al. 2008; M. Shirazi & J. Brinchmann 2012). Furthermore, the WR enrichment signature
is short-lived: it must be captured during the brief WN-dominated phase (tburst
≲ 5 Myr and ΔtWN ≲ 0.3 Myr), before dilution from WC stars, CCSNe, or delayed AGB
enrichment. These timing constraints imply that only a small fraction of the star-forming
galaxies in the distant Universe will be caught in this phase. The detection of
WR-driven N/O enhancement at high redshift thus reflects a brief evolutionary stage
where intense, rapid feedback from a large number of WN stars briefly imprints nonuniform
elemental enrichment patterns (i.e., elevated N/O), which are expected to be quickly
washed away. As soon as the system evolves beyond the WN phase, subsequent WC or
CCSN yields will rapidly dilute the N excess and alter the overall abundance patter
(e.g., increasing C/O, lowering N/C).\r\n\r\nRecently, M. W. Topping et al. (2025b)
showed that galaxies with significant N iv] emission (corresponding to extreme N/O
enhancement), are found exclusively among galaxies with extreme [O iii]+Hβ EWs of
2600–4200 Å. Galaxies with such high [O iii]+Hβ EWs are in the upper 2% tail of
the EW distribution at z ≳ 4 and are outliers at z ∼ 0. This strongly suggests that
high N/O outliers are confined to the youngest stellar populations undergoing their
most intense bursts of star formation in the early Universe (e.g., R. Endsley et
al. 2023, 2025; J. Matthee et al. 2023; M. W. Topping et al. 2025b).\r\n\r\nIn this
context, M. W. Topping et al. (2025b) found that 30% of galaxies with EW[O III]
+ Hβ > 2000 Å show strong nitrogen emission, corresponding to ∼0.6% of their UV-selected
parent population. If this 0.6% population corresponds to enhanced N/O during the
ΔtWN ∼ 0.3 Myr WN phase, it would imply a characteristic burst timescale of ∼50
Myr. A practical consequence is that young bursts substantially increase the light-to-mass
ratios and, thus, the likelihood of detection in flux-limited samples (e.g., C.
A. Mason et al. 2023; J. B. Muñoz et al. 2023; G. Sun et al. 2023). Therefore, the
observed frequency of strong nitrogen emitters at fixed MUV is likely biased high
relative to their intrinsic abundance (e.g., at fixed stellar mass). Given the detectability
bias toward burst phases, this tburst may represent a lower limit, with the true
interval plausibly longer. This timescale is supported by recent analyses of the
scatter in the star-forming main sequence and time-resolved SFR indicators at z
∼ 3–9 that suggest burst cycles of tens-of-megayear timescales (albeit with broad
distributions, e.g., C. Simmonds et al. 2025). Thus, the combination of extreme-EW
selection and N iv] frequency provides a novel timing argument that WN-driven enrichment
is tightly coupled to very young, transient starburst phases beyond cosmic noon.\r\n\r\nTaken
together, the arguments presented in this work suggest that nitrogen outliers are
not exotic exceptions, but rather a brief, WN-enriched phase that any high-redshift
galaxy with sufficiently high SFR surface density can pass through. In contrast,
numerous low-redshift WR galaxies exhibit young populations that include WN and
WC stars but show little or no N/O enhancement (e.g., Y. I. Izotov et al. 2006;
C. Kehrig et al. 2013). This difference underscores that similar stellar populations
do not guarantee the same chemical signatures; instead, the extreme densities, compactness,
and rapid mixing timescales of high-redshift starbursts likely make WN-driven enrichment
both more pronounced and more transient. In this view, N/O outliers in the early
Universe are not anomalies, but rather are the chemical fingerprints of galaxies
caught midburst, showing fleeting yet inevitable markers of early galaxy evolution.\r\n\r\n6.
Conclusions\r\nWe have presented a detailed enrichment scenario by WN stars that
explains the extreme nitrogen enrichment in the metal-poor (∼10% Z⊙), high surface-density
(1.34 × 103 M⊙ pc−2), high-redshift (z = 6.1025), lensed galaxy RXCJ2248-ID3. These
measurements were made possible by exceptionally deep JWST/NIRSpec medium-resolution
spectroscopy of RXCJ2248-ID3, obtained as part of the GLIMPSE-D survey. The unprecedented
depth and S/N of the GLIMPSE-D spectrum allow spectral measurements typically limited
to the nearby Universe, including consistent broad components in the Balmer series
and [O iii] λ4364 and λλ4960,5008 lines, faint [Ar iv] λλ4713,4741 emission, and
signatures of WR stars. Specifically, we detected the emission characteristic of
WN-type stars, including strong N iii λ4642 and broadened He ii λ1640 and λ4687
emission, marking RXCJ2248-ID3 as the most distant galaxy to date with spectroscopic
detections of WR stars.\r\n\r\nWe performed a detailed nebular analysis, self-consistently
measuring the reddening, high-ionization temperature (Te(O+2)), and densities from
five different diagnostics across a wide ionization range. We measure a low reddening
value of from the Hγ/Hβ ratio but find an excess in the Hα/Hβ ratio of 0.204 due
to collisional excitation of Hα. The measured densities span the range of 1.15 ×
103 cm−3 ≤ ne ≤ 2.65 × 105 cm−3 and show strong evidence for nebular density stratification,
with systematically higher densities in the highest-ionization gas and UV emission
tracing gas at higher densities than those traced by optical diagnostics. This structure
implies a highly clumpy, multiphase ISM. We note that such high-density, multiphase
gas leads to densities from optical diagnostics that are biased to the low end of
the density range due to their low critical densities. Therefore, we recommend using
UV density diagnostics because they are more robust in high-density environments:
ne(Si+2), ne(C+2), and ne(N+3) trace the densities in the low-, intermediate-, and
high-ionization gas, respectively. As a result, we measure a direct-method metallicity
of .\r\n\r\nUsing the full rest-UV+optical spectra, we present the first robust,
consistent measurements of N/O abundance in any galaxy using three ionization stages
of nitrogen (N+/O+, N+2/O+2, N+3/O+2). The uniformity of our N/O measurements suggests
that the N/O enrichment is spatially extended and well mixed throughout the ionized
ISM. Empirical trends suggest C/O should follow a similar trend as N/O, and thus
also be enhanced. In contrast, we find C/O to be significantly depleted relative
to N/O, suggesting nonuniform elemental enrichment likely driven by WN stars with
little to no contribution from WC stars.\r\n\r\nThe CNO abundance pattern is best
reproduced by a modified version of the dual-burst chemical evolution model from
C. Kobayashi & A. Ferrara (2024) that reduces the contribution from WC stars relative
to WN stars, as expected in metal-poor environments. The resulting short-lived WN
phase ejects N-rich, C-poor material. We use this chemical evolution model to assess
whether the observed N mass can plausibly arise from the recent star formation in
RXCJ2248-ID3 and estimate an ionized N mass of 435 M⊙. This value is consistent
with the N mass estimated from the observed emission lines of M⊙ if % of the N gas
is ionized.\r\n\r\nThese results demonstrate that standard stellar evolution models
can reproduce both the CNO pattern and the total nitrogen mass observed without
invoking an exotic IMF or enrichment channel. The uniform N/O ratios across multiple
ionization zones further suggest that the WN yields were rapidly mixed into a relatively
pristine ambient ISM, preserving the global enhancement observed in RXCJ2248-ID3.
Although RXCJ2248-ID3 exhibits strong density and temperature stratification, this
structural complexity does not necessarily imply chemical inhomogeneity. The consistent
N/O ratios across ions tracing vastly different physical conditions indicate that
the enriched material was efficiently dispersed throughout the multiphase ISM. In
such a compact (Re ≈ 20 pc), high-pressure environment, turbulent and radiative
mixing can homogenize the chemical composition on timescales comparable to, or shorter
than, the brief WN phase itself, yielding a chemically uniform yet physically clumpy
nebula.\r\n\r\nImportantly, the abundance pattern and physical conditions observed
in RXCJ2248-ID3 can only be explained if the galaxy is caught during a narrow evolutionary
window within a few megayears of a massive, compact starburst when WN stars dominate
chemical feedback. At low metallicity, stars require higher initial masses to reach
the WR phase, making such enrichment episodes rare and dependent on sufficiently
high SFRs to fully populate the upper IMF. Furthermore, the WN phase itself is extremely
short-lived (∼0.03–0.3 Myr) and easily masked by subsequent WC winds, CCSNe, or
AGB stars contributions. These timing and SFR constraints make WR-driven N/O enhancement
a rare phenomenon associated with extreme starburst conditions that are more common
in the early Universe, and which are scarce in the local Universe.\r\n\r\nOur results
suggest that the WN-driven N/O enrichment we observe is not a peculiar property
of a single system, but rather a brief phase that essentially all high-redshift
galaxies (z > 5) with sufficiently high SFR surface densities to produce significant
numbers of WN stars likely undergo. In particular, the work of M. W. Topping et
al. (2025b) can be used to link N/O outliers to the most extreme [O iii]+Hβ EWs.
The observed frequency of such EWs combined with the short lifetime of the WN phase
implies a burst cycle of order ∼50 Myr, consistent with galaxies repeatedly cycling
through short, bursty episodes of enrichment. Thus, the GLIMPSE-D spectrum of RXCJ2248-ID3
provides not only the first direct evidence of WN stars shaping the chemical evolution
of z > 5 galaxies but also a timing argument that situates N/O outliers as a natural,
fleeting, phase of high-redshift star formation.\r\n\r\nTaken together, our findings
are a glimpse into a short-lived phase of chemically selective enrichment from WN
stars at cosmic dawn, providing a physically self-consistent solution to the extreme
N/O enhancement and relative C/O depletion observed in RXCJ2248-ID3 and galaxies
like it. Thus, RXCJ2248-ID3 serves as a benchmark case for interpreting chemically
enriched, stratified, multiphase starbursts in the early Universe.\r\n\r\nAcknowledgments\r\nWe
thank the referee for their thorough review of our calculations and analysis and
for their helpful suggestions, which greatly improved the robustness of our results
and the clarity of the text. This work is based on observations made with the NASA/ESA/CSA
James Webb Space Telescope. The data were obtained from the Mikulski Archive for
Space Telescopes at the Space Telescope Science Institute, which is operated by
the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS 5-03127 for JWST. These observations are associated with program #9223. This
work has received funding from the Swiss State Secretariat for Education, Research
and Innovation (SERI) under contract No. MB22.00072, as well as from the Swiss National
Science Foundation (SNSF) through project grant 200020_207349. The Cosmic Dawn Center
(DAWN) is funded by the Danish National Research Foundation under grant DNRF140.
The Dunlap Institute is funded through an endowment established by the David Dunlap
family and the University of Toronto. We acknowledge the support of the Canadian
Space Agency (CSA) [25JWGO4A06]. HA acknowledges support from CNES, focused on the
JWST mission, and the Programme National Cosmology and Galaxies (PNCG) of CNRS/INSU
with INP and IN2P3, co-funded by CEA and CNES and support by the French National
Research Agency (ANR) under grant ANR-21-CE31-0838. The JWST data presented in this
article from program #9223 were obtained from the Mikulski Archive for Space Telescopes
(MAST) at the Space Telescope Science Institute. The specific observations analyzed
can be accessed via DOI: 10.17909/8642-1k68."
article_number: '112'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Danielle A.
full_name: Berg, Danielle A.
last_name: Berg
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: John
full_name: Chisholm, John
last_name: Chisholm
- first_name: Hakim
full_name: Atek, Hakim
last_name: Atek
- first_name: Seiji
full_name: Fujimoto, Seiji
last_name: Fujimoto
- first_name: Vasily
full_name: Kokorev, Vasily
last_name: Kokorev
- first_name: Lukas J.
full_name: Furtak, Lukas J.
last_name: Furtak
- first_name: Chiaki
full_name: Kobayashi, Chiaki
last_name: Kobayashi
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Angela
full_name: Adamo, Angela
last_name: Adamo
- first_name: Qinyue
full_name: Fei, Qinyue
last_name: Fei
- first_name: Damien
full_name: Korber, Damien
last_name: Korber
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Rui
full_name: Marques-Chaves, Rui
last_name: Marques-Chaves
- first_name: Zorayda
full_name: Martinez, Zorayda
last_name: Martinez
- first_name: Kristen B.W.
full_name: Mcquinn, Kristen B.W.
last_name: Mcquinn
- first_name: Julian B.
full_name: Muñoz, Julian B.
last_name: Muñoz
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Alberto
full_name: Saldana-Lopez, Alberto
last_name: Saldana-Lopez
- first_name: Daniel P.
full_name: Stark, Daniel P.
last_name: Stark
- first_name: Mabel G.
full_name: Stephenson, Mabel G.
last_name: Stephenson
- first_name: Tiger Yu Yang
full_name: Hsiao, Tiger Yu Yang
last_name: Hsiao
citation:
ama: 'Berg DA, Naidu RP, Chisholm J, et al. A fleeting GLIMPSE of N/O enrichment
at cosmic dawn: Evidence for Wolf Rayet N stars in a z = 6.1 galaxy. The Astrophysical
Journal. 2026;1003(2). doi:10.3847/1538-4357/ae5e4c'
apa: 'Berg, D. A., Naidu, R. P., Chisholm, J., Atek, H., Fujimoto, S., Kokorev,
V., … Hsiao, T. Y. Y. (2026). A fleeting GLIMPSE of N/O enrichment at cosmic dawn:
Evidence for Wolf Rayet N stars in a z = 6.1 galaxy. The Astrophysical Journal.
IOP Publishing. https://doi.org/10.3847/1538-4357/ae5e4c'
chicago: 'Berg, Danielle A., Rohan P. Naidu, John Chisholm, Hakim Atek, Seiji Fujimoto,
Vasily Kokorev, Lukas J. Furtak, et al. “A Fleeting GLIMPSE of N/O Enrichment
at Cosmic Dawn: Evidence for Wolf Rayet N Stars in a z = 6.1 Galaxy.” The Astrophysical
Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae5e4c.'
ieee: 'D. A. Berg et al., “A fleeting GLIMPSE of N/O enrichment at cosmic
dawn: Evidence for Wolf Rayet N stars in a z = 6.1 galaxy,” The Astrophysical
Journal, vol. 1003, no. 2. IOP Publishing, 2026.'
ista: 'Berg DA, Naidu RP, Chisholm J, Atek H, Fujimoto S, Kokorev V, Furtak LJ,
Kobayashi C, Schaerer D, Adamo A, Fei Q, Korber D, Matthee JJ, Marques-Chaves
R, Martinez Z, Mcquinn KBW, Muñoz JB, Oesch PA, Saldana-Lopez A, Stark DP, Stephenson
MG, Hsiao TYY. 2026. A fleeting GLIMPSE of N/O enrichment at cosmic dawn: Evidence
for Wolf Rayet N stars in a z = 6.1 galaxy. The Astrophysical Journal. 1003(2),
112.'
mla: 'Berg, Danielle A., et al. “A Fleeting GLIMPSE of N/O Enrichment at Cosmic
Dawn: Evidence for Wolf Rayet N Stars in a z = 6.1 Galaxy.” The Astrophysical
Journal, vol. 1003, no. 2, 112, IOP Publishing, 2026, doi:10.3847/1538-4357/ae5e4c.'
short: D.A. Berg, R.P. Naidu, J. Chisholm, H. Atek, S. Fujimoto, V. Kokorev, L.J.
Furtak, C. Kobayashi, D. Schaerer, A. Adamo, Q. Fei, D. Korber, J.J. Matthee,
R. Marques-Chaves, Z. Martinez, K.B.W. Mcquinn, J.B. Muñoz, P.A. Oesch, A. Saldana-Lopez,
D.P. Stark, M.G. Stephenson, T.Y.Y. Hsiao, The Astrophysical Journal 1003 (2026).
date_created: 2026-05-31T22:02:12Z
date_published: 2026-05-20T00:00:00Z
date_updated: 2026-06-02T08:46:20Z
day: '20'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae5e4c
external_id:
arxiv:
- '2511.13591'
file:
- access_level: open_access
checksum: 1058555fdede45e10fca25d74e7977bc
content_type: application/pdf
creator: dernst
date_created: 2026-06-02T08:46:08Z
date_updated: 2026-06-02T08:46:08Z
file_id: '21938'
file_name: 2026_AstrophysicalJour_Berg.pdf
file_size: 21249354
relation: main_file
success: 1
file_date_updated: 2026-06-02T08:46:08Z
has_accepted_license: '1'
intvolume: ' 1003'
issue: '2'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'A fleeting GLIMPSE of N/O enrichment at cosmic dawn: Evidence for Wolf Rayet
N stars in a z = 6.1 galaxy'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1003
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21997'
abstract:
- lang: eng
text: 'The massive binary common envelope (CE) phase plays a pivotal role in the
formation of close black hole (BH)/neutron star binaries, yet significant uncertainties
remain in our understanding of this process. In this study, we aim to constrain
the massive binary CE phase by systematically reconstructing three observed BH
X-ray binaries (BHXBs): GRO J1655-40, SAX J1819.3-2525, and 4U 1543-47. Through
comprehensive binary evolution simulations and parametric supernova modeling,
we establish lower limits for the CE efficiency parameters under different energy
considerations within the standard energy formalism. Specifically, we derive minimum
values for three cases: α0.5U and αU, representing CE efficiencies with half and
all of the internal energy contributing to the envelope ejection, respectively,
and αH, accounting for the envelope’s enthalpy. Our analysis reveals that the
self-consistent formation of these three BHXBs requires CE efficiency parameters
satisfying α0.5U ≳ 6.7, αU ≳ 4.2, and αH ≳ 1.7. Notably, we find no viable solutions
with CE efficiency values below unity, even when considering the most extreme
scenarios, in which the envelope binding energy is significantly reduced through
enthalpy inclusion. Our results strongly imply that either additional energy sources
are required or the formalism itself must be revised. Furthermore, we quantitatively
assess the impact of BH natal kicks on our results. A key finding is that 4U 1543-47’s
formation requires substantial natal kicks (≳50 km s−1), as lower kick velocities
are incompatible with isolated binary evolution.'
acknowledgement: We deeply thank the referee for a very careful reading and constructive
comments that have led to the improvement of the manuscript. The authors are grateful
to Poshak Gandhi for his valuable suggestions and feedback on this work. This work
is supported by the Natural Science Foundation of China (grant Nos. 12125303, 12525304,
12288102, 12473034, 12103028, 12333008, 12422305, 12090040/3, 12273105, 11703081,
11422324, 12073070, and 12173081), the CAS Project for Young Scientists in Basic
Research (YSBR-148), the Strategic Priority Research Program of the Chinese Academy
of Sciences (grant Nos. XDB1160303, XDB1160201, and XDB1160000), the National Key
R&D Program of China (grant Nos. 2021YFA1600403 and 2021YFA1600400), the Key Research
Program of Frontier Sciences of CAS (No. ZDBS-LY-7005), the “CAS Light of West China”,
the Yunnan Revitalization Talent Support Program-Science & Technology Champion Project
(No. 202305AB350003) and Young Talent Project, the International Centre of Supernovae
(ICESUN), Yunnan Key Laboratory of Supernova Research (Nos. 202302AN360001 and 202201BC070003),
Yunnan Fundamental Research Projects (No. 202401AT070139), and the Natural Science
Foundation of Henan Province (No. 242300420944). X.C. acknowledges the New Cornerstone
Science Foundation through the XPLORER PRIZE. The authors gratefully acknowledge
the “PHOENIX Supercomputing Platform” jointly operated by the Binary Population
Synthesis Group and the Stellar Astrophysics Group at Yunnan Observatories, Chinese
Academy of Sciences.
article_number: '31'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Zhenwei
full_name: Li, Zhenwei
last_name: Li
- first_name: Dandan
full_name: Wei, Dandan
id: 5dd129bd-0601-11ef-b325-833284687b76
last_name: Wei
- first_name: Shi
full_name: Jia, Shi
last_name: Jia
- first_name: Hailiang
full_name: Chen, Hailiang
last_name: Chen
- first_name: Hongwei
full_name: Ge, Hongwei
last_name: Ge
- first_name: Zhuo
full_name: Chen, Zhuo
last_name: Chen
- first_name: Yangyang
full_name: Zhang, Yangyang
last_name: Zhang
- first_name: Xuefei
full_name: Chen, Xuefei
last_name: Chen
- first_name: Zhanwen
full_name: Han, Zhanwen
last_name: Han
citation:
ama: 'Li Z, Wei D, Jia S, et al. A path to constraints on common envelope ejection
in massive binaries: Full evolutionary reconstruction of three Black Hole X-ray
binaries. The Astrophysical Journal. 2026;1004(1). doi:10.3847/1538-4357/ae66fd'
apa: 'Li, Z., Wei, D., Jia, S., Chen, H., Ge, H., Chen, Z., … Han, Z. (2026). A
path to constraints on common envelope ejection in massive binaries: Full evolutionary
reconstruction of three Black Hole X-ray binaries. The Astrophysical Journal.
IOP Publishing. https://doi.org/10.3847/1538-4357/ae66fd'
chicago: 'Li, Zhenwei, Dandan Wei, Shi Jia, Hailiang Chen, Hongwei Ge, Zhuo Chen,
Yangyang Zhang, Xuefei Chen, and Zhanwen Han. “A Path to Constraints on Common
Envelope Ejection in Massive Binaries: Full Evolutionary Reconstruction of Three
Black Hole X-Ray Binaries.” The Astrophysical Journal. IOP Publishing,
2026. https://doi.org/10.3847/1538-4357/ae66fd.'
ieee: 'Z. Li et al., “A path to constraints on common envelope ejection in
massive binaries: Full evolutionary reconstruction of three Black Hole X-ray binaries,”
The Astrophysical Journal, vol. 1004, no. 1. IOP Publishing, 2026.'
ista: 'Li Z, Wei D, Jia S, Chen H, Ge H, Chen Z, Zhang Y, Chen X, Han Z. 2026. A
path to constraints on common envelope ejection in massive binaries: Full evolutionary
reconstruction of three Black Hole X-ray binaries. The Astrophysical Journal.
1004(1), 31.'
mla: 'Li, Zhenwei, et al. “A Path to Constraints on Common Envelope Ejection in
Massive Binaries: Full Evolutionary Reconstruction of Three Black Hole X-Ray Binaries.”
The Astrophysical Journal, vol. 1004, no. 1, 31, IOP Publishing, 2026,
doi:10.3847/1538-4357/ae66fd.'
short: Z. Li, D. Wei, S. Jia, H. Chen, H. Ge, Z. Chen, Y. Zhang, X. Chen, Z. Han,
The Astrophysical Journal 1004 (2026).
date_created: 2026-06-14T22:01:42Z
date_published: 2026-06-10T00:00:00Z
date_updated: 2026-06-19T09:58:52Z
day: '10'
ddc:
- '520'
department:
- _id: YlGo
doi: 10.3847/1538-4357/ae66fd
external_id:
arxiv:
- '2604.10440'
file:
- access_level: open_access
checksum: bb76fbb51f8d2834cb79f19e7932e3bd
content_type: application/pdf
creator: dernst
date_created: 2026-06-19T09:56:29Z
date_updated: 2026-06-19T09:56:29Z
file_id: '22099'
file_name: 2026_AstrophysicalJour_Li.pdf
file_size: 3386217
relation: main_file
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file_date_updated: 2026-06-19T09:56:29Z
has_accepted_license: '1'
intvolume: ' 1004'
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language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'A path to constraints on common envelope ejection in massive binaries: Full
evolutionary reconstruction of three Black Hole X-ray binaries'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1004
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21999'
abstract:
- lang: eng
text: JWST has revealed an abundance of supermassive black holes (BHs) in the early
Universe, and yet the lowest mass seed BHs that gave rise to these populations
remain elusive. Here, we present a systematic search for broad-line active galactic
nuclei (AGNs) in some of the faintest high-z galaxies surveyed yet by combining
ultra-deep JWST/NIRSpec G395M spectroscopy with the strong lensing aid in AS1063.
By employing the profile of the [O iii]λ5007 emission lines as a template for
narrow-line components and carefully cross-validating with mock observations,
we identify a sample of 10 broad-line AGNs at 4.5 < z < 7.0 (eight secure, two
tentative). The inferred BH masses from the broad Hα line explore the intermediate
BH mass regime down to ∼105.5 M⊙. The stellar mass (M*) is estimated with a galaxy+AGN
composite model, and we find the BH to stellar mass ratio spans down to MBH/M*
≲ 0.1%, unveiling populations on the empirical MBH–M* relation observed in the
local Universe. We also derive the BH mass function and investigate its low-mass
end at this epoch. While we confirm the agreement of our results with previous
studies at MBH ≳ 106.5M⊙, we find the mass range of ∼105.5 M⊙ features an enhanced
abundance with respect to the extrapolated best-fit Schechter function. Comparison
with theoretical models suggests that a possible origin for this enhanced abundance
is the direct-collapse BH formation, supporting the scenario that the direct collapse
of massive gas clouds is a significant pathway for the earliest supermassive BHs.
acknowledgement: 'We thank the anonymous referee for insightful comments, which significantly
improved the manuscript. We acknowledge Kohei Inayoshi for helpful discussions.
This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope.
The data were obtained from the Mikulski Archive for Space Telescopes at the Space
Telescope Science Institute, which is operated by the Association of Universities
for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. The specific
observations analyzed can be accessed via DOI: 10.17909/4byn-fe55 and 10.17909/v2y7-j922.
These observations are associated with programs #3293 and #9223. S.F. and Q.F. acknowledge
support from the Dunlap Institute, which is funded through an endowment established
by the David Dunlap family and the University of Toronto. A.S.L. acknowledges support
from the Knut and Alice Wallenberg Foundation. A.Z. acknowledges support by grant
No. 2020750 from the United States-Israel Binational Science Foundation (BSF) and
grant No. 2109066 from the United States National Science Foundation (NSF); and
by the Israel Science Foundation grant No. 864/23.'
article_number: '244'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Qinyue
full_name: Fei, Qinyue
last_name: Fei
- first_name: Seiji
full_name: Fujimoto, Seiji
last_name: Fujimoto
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: John
full_name: Chisholm, John
last_name: Chisholm
- first_name: Hakim
full_name: Atek, Hakim
last_name: Atek
- first_name: Gabriel
full_name: Brammer, Gabriel
last_name: Brammer
- first_name: Yoshihisa
full_name: Asada, Yoshihisa
last_name: Asada
- first_name: Danielle A.
full_name: Berg, Danielle A.
last_name: Berg
- first_name: Volker
full_name: Bromm, Volker
last_name: Bromm
- first_name: Lukas J.
full_name: Furtak, Lukas J.
last_name: Furtak
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Tiger Yu Yang
full_name: Hsiao, Tiger Yu Yang
last_name: Hsiao
- first_name: Junehyoung
full_name: Jeon, Junehyoung
last_name: Jeon
- first_name: Vasily
full_name: Kokorev, Vasily
last_name: Kokorev
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Priyamvada
full_name: Natarajan, Priyamvada
last_name: Natarajan
- first_name: Richard
full_name: Pan, Richard
last_name: Pan
- first_name: Johan
full_name: Richard, Johan
last_name: Richard
- first_name: Alberto
full_name: Saldana-Lopez, Alberto
last_name: Saldana-Lopez
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Marta
full_name: Volonteri, Marta
last_name: Volonteri
- first_name: Adi
full_name: Zitrin, Adi
last_name: Zitrin
citation:
ama: 'Fei Q, Fujimoto S, Naidu RP, et al. A GLIMPSE of intermediate mass Black Holes
in the epoch of reionization: Witnessing the descendants of direct collapse? The
Astrophysical Journal. 2026;1003(2). doi:10.3847/1538-4357/ae6248'
apa: 'Fei, Q., Fujimoto, S., Naidu, R. P., Chisholm, J., Atek, H., Brammer, G.,
… Zitrin, A. (2026). A GLIMPSE of intermediate mass Black Holes in the epoch of
reionization: Witnessing the descendants of direct collapse? The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae6248'
chicago: 'Fei, Qinyue, Seiji Fujimoto, Rohan P. Naidu, John Chisholm, Hakim Atek,
Gabriel Brammer, Yoshihisa Asada, et al. “A GLIMPSE of Intermediate Mass Black
Holes in the Epoch of Reionization: Witnessing the Descendants of Direct Collapse?”
The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae6248.'
ieee: 'Q. Fei et al., “A GLIMPSE of intermediate mass Black Holes in the
epoch of reionization: Witnessing the descendants of direct collapse?,” The
Astrophysical Journal, vol. 1003, no. 2. IOP Publishing, 2026.'
ista: 'Fei Q, Fujimoto S, Naidu RP, Chisholm J, Atek H, Brammer G, Asada Y, Berg
DA, Bromm V, Furtak LJ, Greene JE, Hsiao TYY, Jeon J, Kokorev V, Matthee JJ, Natarajan
P, Pan R, Richard J, Saldana-Lopez A, Schaerer D, Volonteri M, Zitrin A. 2026.
A GLIMPSE of intermediate mass Black Holes in the epoch of reionization: Witnessing
the descendants of direct collapse? The Astrophysical Journal. 1003(2), 244.'
mla: 'Fei, Qinyue, et al. “A GLIMPSE of Intermediate Mass Black Holes in the Epoch
of Reionization: Witnessing the Descendants of Direct Collapse?” The Astrophysical
Journal, vol. 1003, no. 2, 244, IOP Publishing, 2026, doi:10.3847/1538-4357/ae6248.'
short: Q. Fei, S. Fujimoto, R.P. Naidu, J. Chisholm, H. Atek, G. Brammer, Y. Asada,
D.A. Berg, V. Bromm, L.J. Furtak, J.E. Greene, T.Y.Y. Hsiao, J. Jeon, V. Kokorev,
J.J. Matthee, P. Natarajan, R. Pan, J. Richard, A. Saldana-Lopez, D. Schaerer,
M. Volonteri, A. Zitrin, The Astrophysical Journal 1003 (2026).
das_tickbox: '0'
dataavailabilitystatement: '10.17909/4byn-fe55 and 10.17909/v2y7-j922 used with Software:
LMFIT (M. Newville et al. 2014) msafit (A. de Graaff et al. 2024). - Text extracted
from Acknowledgements, no separate DAS'
date_created: 2026-06-14T22:01:43Z
date_published: 2026-06-01T00:00:00Z
date_updated: 2026-06-22T11:34:52Z
day: '01'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae6248
external_id:
arxiv:
- '2509.20452'
file:
- access_level: open_access
checksum: b04247996b8dcd0eb5387581706d1106
content_type: application/pdf
creator: dernst
date_created: 2026-06-22T08:03:55Z
date_updated: 2026-06-22T08:03:55Z
file_id: '22112'
file_name: 2026_AstrophysicalJour_Fei.pdf
file_size: 19681834
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has_accepted_license: '1'
intvolume: ' 1003'
issue: '2'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
researchdata_availability: yes
scopus_import: '1'
status: public
supplementarymaterial: yes
title: 'A GLIMPSE of intermediate mass Black Holes in the epoch of reionization: Witnessing
the descendants of direct collapse?'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1003
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21724'
abstract:
- lang: eng
text: 'The next generation of weak-gravitational-lensing surveys has the potential
to place stringent constraints on cosmological parameters. However, their analysis
is limited by systematics such as the intrinsic alignments of galaxies, which
alter weak-lensing convergence and can lead to biases in cosmological parameter
estimations. For the first time, in this work, we investigate the impact of intrinsic
alignments on non-Gaussian statistics of the weak-lensing field using galaxy shapes
derived from the IllustrisTNG hydrodynamical simulation. We create two catalogs
of ray-traced convergence maps: one that includes the measured intrinsic shape
of each galaxy and another where all galaxies are randomly rotated to eliminate
intrinsic alignments. We compare a range of weak-lensing statistics between the
two catalogs, including the shear–shear correlation function, the map-level angular
power spectrum, one-point, peak count, and minimum distribution functions, and
Minkowski functionals. For each statistic, we assess the level of statistical
distinguishability between catalogs for a set of future survey angular areas.
Our results reveal strong small-scale correlation in the alignment of galaxies
and statistically significant boosts in weak-lensing convergence in both positive
and negative directions for high-significance peaks and minima, respectively.
We note that our analysis is at a fixed number density of ˜ 5 arcmin^-2, drawn
from a single realization of initial conditions, and does not include observational
uncertainties or supersample covariance contributions. Weak-lensing analyses utilizing
non-Gaussian statistics must account for intrinsic alignments to avoid significantly
compromised cosmological inferences.'
acknowledgement: We thank Fulvio Ferlito, Ana Maria Delgado, and Ken Osato for helpful
conversations during this work. M.E.L. is supported by NSF grant DGE-2036197. Z.H.
acknowledges financial support from NASA ATP grant 80NSSC24K1093. The Flatiron Institute
is supported by the Simons Foundation.
article_number: '36'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Max E.
full_name: Lee, Max E.
last_name: Lee
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
orcid: 0000-0003-3633-5403
- first_name: Shivam
full_name: Pandey, Shivam
last_name: Pandey
- first_name: Shy
full_name: Genel, Shy
last_name: Genel
citation:
ama: Lee ME, Haiman Z, Pandey S, Genel S. The effect of intrinsic alignments on
weak-lensing statistics in hydrodynamical simulations. The Astrophysical Journal.
2025;996(1). doi:10.3847/1538-4357/ae1ca7
apa: Lee, M. E., Haiman, Z., Pandey, S., & Genel, S. (2025). The effect of intrinsic
alignments on weak-lensing statistics in hydrodynamical simulations. The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae1ca7
chicago: Lee, Max E., Zoltán Haiman, Shivam Pandey, and Shy Genel. “The Effect of
Intrinsic Alignments on Weak-Lensing Statistics in Hydrodynamical Simulations.”
The Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/ae1ca7.
ieee: M. E. Lee, Z. Haiman, S. Pandey, and S. Genel, “The effect of intrinsic alignments
on weak-lensing statistics in hydrodynamical simulations,” The Astrophysical
Journal, vol. 996, no. 1. IOP Publishing, 2025.
ista: Lee ME, Haiman Z, Pandey S, Genel S. 2025. The effect of intrinsic alignments
on weak-lensing statistics in hydrodynamical simulations. The Astrophysical Journal.
996(1), 36.
mla: Lee, Max E., et al. “The Effect of Intrinsic Alignments on Weak-Lensing Statistics
in Hydrodynamical Simulations.” The Astrophysical Journal, vol. 996, no.
1, 36, IOP Publishing, 2025, doi:10.3847/1538-4357/ae1ca7.
short: M.E. Lee, Z. Haiman, S. Pandey, S. Genel, The Astrophysical Journal 996 (2025).
date_created: 2026-04-12T22:01:52Z
date_published: 2025-12-23T00:00:00Z
date_updated: 2026-04-13T08:30:52Z
day: '23'
ddc:
- '520'
department:
- _id: ZoHa
doi: 10.3847/1538-4357/ae1ca7
external_id:
arxiv:
- '2504.12460'
file:
- access_level: open_access
checksum: 0d8fa05617420230eac39944b36839e9
content_type: application/pdf
creator: dernst
date_created: 2026-04-13T08:20:16Z
date_updated: 2026-04-13T08:20:16Z
file_id: '21732'
file_name: 2025_AstrophysicalJournal_Lee.pdf
file_size: 4122087
relation: main_file
success: 1
file_date_updated: 2026-04-13T08:20:16Z
has_accepted_license: '1'
intvolume: ' 996'
issue: '1'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: The effect of intrinsic alignments on weak-lensing statistics in hydrodynamical
simulations
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 996
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21727'
abstract:
- lang: eng
text: We present a comprehensive analysis of the MIRI Extremely Red Object Virgil,
a Lyα emitter at zspec = 6.6379 ± 0.0035 with the photometric properties of a
Little Red Dot. Leveraging new JWST/MIRI imaging from the MIDIS and PAHSPECS programs,
we confirm Virgil’s extraordinary nature among galaxies in JADES/GOODS-South,
exhibiting a strikingly red NIRCam-to-MIRI color (F444W–F1500W = 2.84 ± 0.04 mag).
Deep NIRSpec/PRISM spectroscopy from the OASIS program offers key insights into
the host galaxy, revealing properties of an average star-forming galaxy during
Cosmic Reionization, such as a subsolar metallicity, low-to-moderate dust content,
and a relatively high ionization parameter and electron temperature. By estimating
the star formation rate of Virgil from UV and Hα, we find evidence that the galaxy
is either entering or fading out of a bursty episode. Although line-ratio diagnostics
employed at high z would classify Virgil as an active galactic nucleus (AGN),
this classification becomes ambiguous once redshift evolution is considered. Nonetheless,
Virgil occupies the same parameter space as recently confirmed AGNs at similar
redshifts. The new deep MIRI data at 15 μm reinforce the AGN nature of Virgil,
as inferred from multiple spectral energy distribution (SED) fitting codes. Virgil’s
rising infrared SED and UV excess resemble those of Dust-Obscured Galaxies (DOGs)
studied with Spitzer at Cosmic Noon, particularly blue-excess HotDOGs. Our results
highlight the need for a multiwavelength approach incorporating MIRI to uncover
such extreme sources at z ≳ 6 and to shed light on the interplay between galaxy
evolution and early black hole growth during Cosmic Reionization.
acknowledgement: "The authors are deeply grateful to Antonello Calabrò for valuable
insights on CLOUDY and pyCloudy, and for publicly sharing their SFG and AGN models,
which were used as a reference to verify the consistency of our photoionization
models. The authors also thank Adam Carnall for insightful input on bagpipes and
for assistance with the implementation of the two-population model adopted in this
work. Finally, they also thank Camilla Pacifici, Vasily Kokorev, and Cristian Vignali
for their insightful discussions.\r\n\r\nThis work is based on observations made
with the NASA/ESA/CSA JWST. The data were obtained from the Mikulski Archive for
Space Telescopes (MAST) at the Space Telescope Science Institute, which is operated
by the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS 5-03127 for JWST. These observations are associated with JWST programs GTO #1180,
GO #1210, GTO#1283, GO #1963, GO #1895, GO# 3215, and GO#6511.\r\n\r\nThe authors
acknowledge the FRESCO, JEMS, and #3215 teams led by co-PIs P. Oesch, C. C. Williams,
M. Maseda, D. Eisenstein, and R. Maiolino for developing their observing program
with a zero-exclusive-access period. Processing for the JADES NIRCam data release
was performed on the lux cluster at the University of California, Santa Cruz, funded
by NSF MRI grant AST 1828315. Also based on observations made with the NASA/ESA
Hubble Space Telescope obtained from the Space Telescope Science Institute, which
is operated by the Association of Universities for Research in Astronomy, Inc.,
under NASA contract NAS 526555. The data presented in this article were obtained
from MAST at the Space Telescope Science Institute. The specific observations analyzed
can be accessed via doi: 10.17909/1rq3-8048 P. Oesch & D. Magee (2023), C. Williams
et al. (2023), G. Illingworth (2015), and M. Rieke et al. (2023).\r\n\r\nA.J.B.
acknowledges funding from the “FirstGalaxies” Advanced Grant from the European Research
Council (ERC) under the European Union’s Horizon 2020 research and innovation program
(grant agreement No. 789056).\r\n\r\nP.G.P.-G. acknowledges support from grant PID2022-139567NB-I00
funded by the Spanish Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033,
FEDER, UE.\r\n\r\nB.E.R. acknowledges support from the NIRCam Science Team contract
to the University of Arizona, NAS5-02015, and JWST Program 3215.\r\n\r\nS.T. acknowledges
support by the Royal Society Research Grant G125142.\r\n\r\nThe research of C.C.W.
is supported by NOIRLab, which is managed by the Association of Universities for
Research in Astronomy (AURA) under a cooperative agreement with the National Science
Foundation.\r\n\r\nJ.W. gratefully acknowledges support from the Cosmic Dawn Center
through the DAWN Fellowship. The Cosmic Dawn Center (DAWN) is funded by the Danish
National Research Foundation under grant No. 140.\r\n\r\nY.Z., Z.J., and P.L. gratefully
acknowledge the JWST/NIRCam contract to the University of Arizona NAS5-02015.\r\n\r\nThe
work of G.H.R. and P.L. was also supported by grant 80NSSC18K0555, from the NASA
Goddard Space Flight Center to the University of Arizona.\r\n\r\nH.Ü. acknowledges
funding by the European Union (ERC APEX, 101164796). Views and opinions expressed
are however those of the authors only and do not necessarily reflect those of the
European Union or the European Research Council Executive Agency. Neither the European
Union nor the granting authority can be held responsible for them.\r\n\r\nG.C.J.
acknowledges support by the Science and Technology Facilities Council (STFC), ERC
Advanced grant 695671 “QUENCH.”\r\n\r\nA.C.G. acknowledges support by JWST contract
B0215/JWST-GO-02926.\r\n\r\nG.O. acknowledges support from the Swedish National
Space Agency (SNSA).\r\n\r\nH.I. acknowledges support from JSPS KAKENHI grant No.
JP21H01129.\r\n\r\nM.A. gratefully acknowledges support from ANID Basal Project
FB210003 and ANID MILENIO NCN2024_112.\r\n\r\nT.D.S. acknowledges the research project
was supported by the Hellenic Foundation for Research and Innovation (HFRI) under
the “2nd Call for HFRI Research Projects to Support Faculty Members and Researchers”
(project No.: 03382).\r\n\r\nR.M. acknowledges support by the Science and Technology
Facilities Council (STFC), by the ERC through Advanced grant 695671 “QUENCH,” and
by the UKRI Frontier Research grant RISEandFALL. R.M. also acknowledges funding
from a research professorship from the Royal Society.\r\n\r\nI.S. acknowledges funding
from the Atraccíon de Talento grant No. 2022-T1/TIC-20472 of the Comunidad de Madrid,
Spain, and the European Research Council (ERC) under the European Union’s Horizon
2020 research and innovation program (grant No. 101117541, DistantDust).\r\n\r\nK.I.C.
acknowledges funding from the Dutch Research Council (NWO) through the award of
the Vici grant VI.C.212.036.\r\n\r\nFacilities: HST - Hubble Space Telescope satellite,
JWST. -\r\n\r\nSoftware: Astropy (Astropy Collaboration et al. 2022), Bagpipes (A.
C. Carnall et al. 2019), MSAEXP (G. Brammer 2023) NumPy (C. R. Harris et al. 2020),
pandas (The pandas development team 2024) Photutils (L. Bradley et al. 2016), TOPCAT
(M. Taylor 2022)."
article_number: '86'
article_processing_charge: Yes
article_type: original
author:
- first_name: Pierluigi
full_name: Rinaldi, Pierluigi
last_name: Rinaldi
- first_name: Pablo G.
full_name: Pérez-González, Pablo G.
last_name: Pérez-González
- first_name: George H.
full_name: Rieke, George H.
last_name: Rieke
- first_name: Jianwei
full_name: Lyu, Jianwei
last_name: Lyu
- first_name: Francesco
full_name: D’Eugenio, Francesco
last_name: D’Eugenio
- first_name: Zihao
full_name: Wu, Zihao
last_name: Wu
- first_name: Stefano
full_name: Carniani, Stefano
last_name: Carniani
- first_name: Tobias J.
full_name: Looser, Tobias J.
last_name: Looser
- first_name: Irene
full_name: Shivaei, Irene
last_name: Shivaei
- first_name: Leindert A.
full_name: Boogaard, Leindert A.
last_name: Boogaard
- first_name: Tanio
full_name: Diaz-Santos, Tanio
last_name: Diaz-Santos
- first_name: Luis
full_name: Colina, Luis
last_name: Colina
- first_name: Göran
full_name: Östlin, Göran
last_name: Östlin
- first_name: Stacey
full_name: Alberts, Stacey
last_name: Alberts
- first_name: Javier
full_name: Álvarez-Márquez, Javier
last_name: Álvarez-Márquez
- first_name: Marianna
full_name: Annuziatella, Marianna
last_name: Annuziatella
- first_name: Manuel
full_name: Aravena, Manuel
last_name: Aravena
- first_name: Rachana
full_name: Bhatawdekar, Rachana
last_name: Bhatawdekar
- first_name: Andrew J.
full_name: Bunker, Andrew J.
last_name: Bunker
- first_name: Karina I.
full_name: Caputi, Karina I.
last_name: Caputi
- first_name: Stéphane
full_name: Charlot, Stéphane
last_name: Charlot
- first_name: Alejandro
full_name: Crespo Gómez, Alejandro
last_name: Crespo Gómez
- first_name: Mirko
full_name: Curti, Mirko
last_name: Curti
- first_name: Andreas
full_name: Eckart, Andreas
last_name: Eckart
- first_name: Steven
full_name: Gillman, Steven
last_name: Gillman
- first_name: Kevin
full_name: Hainline, Kevin
last_name: Hainline
- first_name: Nimisha
full_name: Kumari, Nimisha
last_name: Kumari
- first_name: Jens
full_name: Hjorth, Jens
last_name: Hjorth
- first_name: Edoardo
full_name: Iani, Edoardo
id: 4053390a-6b68-11ef-9828-a3b8adef8d0a
last_name: Iani
orcid: 0000-0001-8386-3546
- first_name: Hanae
full_name: Inami, Hanae
last_name: Inami
- first_name: Zhiyuan
full_name: Ji, Zhiyuan
last_name: Ji
- first_name: Benjamin D.
full_name: Johnson, Benjamin D.
last_name: Johnson
- first_name: Gareth C.
full_name: Jones, Gareth C.
last_name: Jones
- first_name: Álvaro
full_name: Labiano, Álvaro
last_name: Labiano
- first_name: Roberto
full_name: Maiolino, Roberto
last_name: Maiolino
- first_name: Jens
full_name: Melinder, Jens
last_name: Melinder
- first_name: Thibaud
full_name: Moutard, Thibaud
last_name: Moutard
- first_name: Florian
full_name: Peissker, Florian
last_name: Peissker
- first_name: Marcia
full_name: Rieke, Marcia
last_name: Rieke
- first_name: Brant
full_name: Robertson, Brant
last_name: Robertson
- first_name: Jan
full_name: Scholtz, Jan
last_name: Scholtz
- first_name: Sandro
full_name: Tacchella, Sandro
last_name: Tacchella
- first_name: Paul P.
full_name: Van Der Werf, Paul P.
last_name: Van Der Werf
- first_name: Fabian
full_name: Walter, Fabian
last_name: Walter
- first_name: Christina C.
full_name: Williams, Christina C.
last_name: Williams
- first_name: Chris
full_name: Willott, Chris
last_name: Willott
- first_name: Joris
full_name: Witstok, Joris
last_name: Witstok
- first_name: Hannah
full_name: Übler, Hannah
last_name: Übler
- first_name: Yongda
full_name: Zhu, Yongda
last_name: Zhu
citation:
ama: 'Rinaldi P, Pérez-González PG, Rieke GH, et al. Deciphering the nature of Virgil:
An obscured active galactic nucleus lurking within an apparently normal Lyα emitter
during cosmic reionization. The Astrophysical Journal. 2025;994(1). doi:10.3847/1538-4357/ae089c'
apa: 'Rinaldi, P., Pérez-González, P. G., Rieke, G. H., Lyu, J., D’Eugenio, F.,
Wu, Z., … Zhu, Y. (2025). Deciphering the nature of Virgil: An obscured active
galactic nucleus lurking within an apparently normal Lyα emitter during cosmic
reionization. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae089c'
chicago: 'Rinaldi, Pierluigi, Pablo G. Pérez-González, George H. Rieke, Jianwei
Lyu, Francesco D’Eugenio, Zihao Wu, Stefano Carniani, et al. “Deciphering the
Nature of Virgil: An Obscured Active Galactic Nucleus Lurking within an Apparently
Normal Lyα Emitter during Cosmic Reionization.” The Astrophysical Journal.
IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/ae089c.'
ieee: 'P. Rinaldi et al., “Deciphering the nature of Virgil: An obscured
active galactic nucleus lurking within an apparently normal Lyα emitter during
cosmic reionization,” The Astrophysical Journal, vol. 994, no. 1. IOP Publishing,
2025.'
ista: 'Rinaldi P, Pérez-González PG, Rieke GH, Lyu J, D’Eugenio F, Wu Z, Carniani
S, Looser TJ, Shivaei I, Boogaard LA, Diaz-Santos T, Colina L, Östlin G, Alberts
S, Álvarez-Márquez J, Annuziatella M, Aravena M, Bhatawdekar R, Bunker AJ, Caputi
KI, Charlot S, Crespo Gómez A, Curti M, Eckart A, Gillman S, Hainline K, Kumari
N, Hjorth J, Iani E, Inami H, Ji Z, Johnson BD, Jones GC, Labiano Á, Maiolino
R, Melinder J, Moutard T, Peissker F, Rieke M, Robertson B, Scholtz J, Tacchella
S, Van Der Werf PP, Walter F, Williams CC, Willott C, Witstok J, Übler H, Zhu
Y. 2025. Deciphering the nature of Virgil: An obscured active galactic nucleus
lurking within an apparently normal Lyα emitter during cosmic reionization. The
Astrophysical Journal. 994(1), 86.'
mla: 'Rinaldi, Pierluigi, et al. “Deciphering the Nature of Virgil: An Obscured
Active Galactic Nucleus Lurking within an Apparently Normal Lyα Emitter during
Cosmic Reionization.” The Astrophysical Journal, vol. 994, no. 1, 86, IOP
Publishing, 2025, doi:10.3847/1538-4357/ae089c.'
short: P. Rinaldi, P.G. Pérez-González, G.H. Rieke, J. Lyu, F. D’Eugenio, Z. Wu,
S. Carniani, T.J. Looser, I. Shivaei, L.A. Boogaard, T. Diaz-Santos, L. Colina,
G. Östlin, S. Alberts, J. Álvarez-Márquez, M. Annuziatella, M. Aravena, R. Bhatawdekar,
A.J. Bunker, K.I. Caputi, S. Charlot, A. Crespo Gómez, M. Curti, A. Eckart, S.
Gillman, K. Hainline, N. Kumari, J. Hjorth, E. Iani, H. Inami, Z. Ji, B.D. Johnson,
G.C. Jones, Á. Labiano, R. Maiolino, J. Melinder, T. Moutard, F. Peissker, M.
Rieke, B. Robertson, J. Scholtz, S. Tacchella, P.P. Van Der Werf, F. Walter, C.C.
Williams, C. Willott, J. Witstok, H. Übler, Y. Zhu, The Astrophysical Journal
994 (2025).
date_created: 2026-04-12T22:01:53Z
date_published: 2025-11-20T00:00:00Z
date_updated: 2026-04-13T07:54:11Z
day: '20'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae089c
file:
- access_level: open_access
checksum: 5d13b0ad3e9f56cbe29c5de0ba5757c8
content_type: application/pdf
creator: dernst
date_created: 2026-04-13T07:53:00Z
date_updated: 2026-04-13T07:53:00Z
file_id: '21731'
file_name: 2025_AstrophysicalJournal_Rinaldi.pdf
file_size: 10298729
relation: main_file
success: 1
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has_accepted_license: '1'
intvolume: ' 994'
issue: '1'
language:
- iso: eng
month: '11'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Deciphering the nature of Virgil: An obscured active galactic nucleus lurking
within an apparently normal Lyα emitter during cosmic reionization'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 994
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '19365'
abstract:
- lang: eng
text: We present a comprehensive analysis of H i absorption around 96 Lyα emitters
(LAEs) at z ≈ 3.3 (median Lyα luminosity ≈1042 erg s−1). These LAEs were identified
within eight MUSE fields, each (math. formular) on the sky and centered on a bright
background quasar, as part of the MUSEQuBES survey. Using Voigt profile fitting
for all H i absorbers detected within ±500 km s−1 of these LAEs, we compiled
a catalog of 800 H i absorption components. Our analysis shows that H i absorption
is enhanced near the LAEs compared to the intergalactic medium. However, no trend
is found between the column densities of H i absorbers and their impact parameters
from the LAEs (spanning ≈54–260 pkpc). Additionally, all galaxies associated
with Lyman-limit systems have impact parameters >50 pkpc from the quasar sightlines,
suggesting that true absorber hosts may be too faint to detect. The LAEs show
an overall H i covering fraction (fc(H i)) of ≈88% for a threshold (math. formular)
(H i) = 15. Notably, at the same threshold, the LAEs in pairs/groups exhibit a
100% H i covering fraction out to ≈250 pkpc. In contrast, isolated LAEs consistently
show a lower fc(H i) of ≈80%. This environmental influence on fc(H i) is also
evident up to ≈300 km s−1 in differential bins of line-of-sight velocity. We find
an anticorrelation between fc(H i) and the equivalent width of rest-frame Lyα
emission (EW0). Based on the Lyα shell model, this could imply that gas-rich galaxies
tend to reside in gas-rich environments or that the LAEs with higher EW0 are more
efficient at ionizing their surrounding medium.
acknowledgement: "We would like to thank the anonymous referee for useful comments.
We thank Marijke Segers, Lorrie Straka, and Monica Turner for their early contributions
to the MUSEQuBES project. We thank Raghunathan Srianand for useful suggestions.
E.B. thanks Labanya Kumar Guha and Yucheng Guo for helpful discussions. S.C. gratefully
acknowledges the fund support from the European Research Council (ERC).\r\n\r\nSoftware:
NumPy (C. R. Harris et al. 2020), SciPy (P. Virtanen et al. 2020), Matplotlib (J.
D. Hunter 2007), and AstroPy (Astropy Collaboration et al. 2013, 2018)."
article_number: '171'
article_processing_charge: Yes
article_type: original
author:
- first_name: Eshita
full_name: Banerjee, Eshita
last_name: Banerjee
- first_name: Sowgat
full_name: Muzahid, Sowgat
last_name: Muzahid
- first_name: Joop
full_name: Schaye, Joop
last_name: Schaye
- first_name: Jérémy
full_name: Blaizot, Jérémy
last_name: Blaizot
- first_name: Nicolas
full_name: Bouché, Nicolas
last_name: Bouché
- first_name: Sebastiano
full_name: Cantalupo, Sebastiano
last_name: Cantalupo
- first_name: Sean D.
full_name: Johnson, Sean D.
last_name: Johnson
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Anne
full_name: Verhamme, Anne
last_name: Verhamme
citation:
ama: 'Banerjee E, Muzahid S, Schaye J, et al. MUSEQuBES: Connecting H i Absorption
with Lyα emitters at z ≈ 3.3. The Astrophysical Journal. 2025;980(2). doi:10.3847/1538-4357/ada7e9'
apa: 'Banerjee, E., Muzahid, S., Schaye, J., Blaizot, J., Bouché, N., Cantalupo,
S., … Verhamme, A. (2025). MUSEQuBES: Connecting H i Absorption with Lyα emitters
at z ≈ 3.3. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ada7e9'
chicago: 'Banerjee, Eshita, Sowgat Muzahid, Joop Schaye, Jérémy Blaizot, Nicolas
Bouché, Sebastiano Cantalupo, Sean D. Johnson, Jorryt J Matthee, and Anne Verhamme.
“MUSEQuBES: Connecting H i Absorption with Lyα Emitters at z ≈ 3.3.” The Astrophysical
Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/ada7e9.'
ieee: 'E. Banerjee et al., “MUSEQuBES: Connecting H i Absorption with Lyα
emitters at z ≈ 3.3,” The Astrophysical Journal, vol. 980, no. 2. IOP Publishing,
2025.'
ista: 'Banerjee E, Muzahid S, Schaye J, Blaizot J, Bouché N, Cantalupo S, Johnson
SD, Matthee JJ, Verhamme A. 2025. MUSEQuBES: Connecting H i Absorption with Lyα
emitters at z ≈ 3.3. The Astrophysical Journal. 980(2), 171.'
mla: 'Banerjee, Eshita, et al. “MUSEQuBES: Connecting H i Absorption with Lyα Emitters
at z ≈ 3.3.” The Astrophysical Journal, vol. 980, no. 2, 171, IOP Publishing,
2025, doi:10.3847/1538-4357/ada7e9.'
short: E. Banerjee, S. Muzahid, J. Schaye, J. Blaizot, N. Bouché, S. Cantalupo,
S.D. Johnson, J.J. Matthee, A. Verhamme, The Astrophysical Journal 980 (2025).
date_created: 2025-03-09T23:01:26Z
date_published: 2025-02-20T00:00:00Z
date_updated: 2026-02-16T12:42:00Z
day: '20'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ada7e9
external_id:
isi:
- '001421001500001'
file:
- access_level: open_access
checksum: 1d33a8eb59f42a0c7a943c8859e9b883
content_type: application/pdf
creator: dernst
date_created: 2025-03-10T11:54:52Z
date_updated: 2025-03-10T11:54:52Z
file_id: '19379'
file_name: 2025_AstrophysicalJour_Banerjee.pdf
file_size: 1194131
relation: main_file
success: 1
file_date_updated: 2025-03-10T11:54:52Z
has_accepted_license: '1'
intvolume: ' 980'
isi: 1
issue: '2'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'MUSEQuBES: Connecting H i Absorption with Lyα emitters at z ≈ 3.3'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 980
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '19596'
abstract:
- lang: eng
text: "We report the spectroscopic discovery of a massive quiescent galaxy at zspec
= 7.29 ± 0.01, just ∼700 Myr after the big bang. RUBIES-UDS-QG-z7 was selected
from public JWST/NIRCam and MIRI imaging from the PRIMER survey and observed with
JWST/NIRSpec as part of RUBIES. The NIRSpec/PRISM spectrum reveals one of the
strongest Balmer breaks observed thus far at z > 6, with no emission lines but
tentative Balmer and Ca absorption features, as well as a Lyman break. Simultaneous
modeling of the NIRSpec/PRISM spectrum and NIRCam and MIRI photometry (spanning
0.9–18 μm) shows that the galaxy formed a stellar mass of\r\n(math. formular)
before z ∼ 8 and ceased forming stars 50–100 Myr prior to the time of observation,
resulting in log (sSFR/Gyr- 1) < -1 . We measure a small physical size of (math
formular) , which implies a high stellarmass surface density within the effective
radius of (math formular) comparable to the highest densities measured in quiescent
galaxies at z ∼ 2–5. The 3D stellar-mass density profile of RUBIES-UDS-QG-z7 is
remarkably similar to the central densities of local massive ellipticals, suggesting
that at least some of their cores may have already been in place at z > 7. The
discovery of RUBIES-UDS-QG-z7 has strong implications for galaxy formation models:
the estimated number density of quiescent galaxies at z ∼ 7 is >100 × larger than
predicted from any model to date, indicating that quiescent galaxies have formed
earlier than previously expected. "
acknowledgement: "We thank the PRIMER team for making their imaging data publicly
available immediately. This work is based on observations made with the NASA/ESA/CSA
James Webb Space Telescope. The data were obtained from the Mikulski Archive for
Space Telescopes at the Space Telescope Science Institute, which is operated by
the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS 5-03127 for JWST. These observations are associated with program #4233. Support
for program #4233 was provided by NASA through a grant from the Space Telescope
Science Institute, which is operated by the Association of Universities for Research
in Astronomy, Inc., under NASA contract NAS 5-03127. This research was supported
by the International Space Science Institute (ISSI) in Bern, through ISSI International
Team project #562. The Cosmic Dawn Center is funded by the Danish National Research
Foundation (DNRF140). This work has received funding from the Swiss State Secretariat
for Education, Research and Innovation (SERI), under contract number MB22.00072,
as well as from the Swiss National Science Foundation (SNSF), through project grant
200020_207349. Support for this work was provided by The Brinson Foundation through
a Brinson Prize Fellowship grant. Support for this work for R.P.N. was provided
by NASA through the NASA Hubble Fellowship grant HST-HF2-51515.001-A, awarded by
the Space Telescope Science Institute, which is operated by the Association of Universities
for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. T.B.M.
was supported by a CIERA fellowship.\r\nAll software packages used in this work
are publicly available on Github: grizli, msafit, msaexp, Prospector, and sedpy.
We acknowledge: astropy (Astropy Collaboration et al. 2013, 2018, 2022), matplotlib
(J. D. Hunter 2007), numpy (C. R. Harris et al. 2020), scipy (P. Virtanen et al.
2020), lmfit (M. Newville et al. 2024), eMPT (N. Bonaventura et al. 2023), the jwst
pipeline (H. Bushouse et al. 2024), msaexp (G. Brammer 2024a), and grizli (G. Brammer
2024b),."
article_number: '11'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Andrea
full_name: Weibel, Andrea
last_name: Weibel
- first_name: Anna
full_name: De Graaff, Anna
last_name: De Graaff
- first_name: David J.
full_name: Setton, David J.
last_name: Setton
- first_name: Tim B.
full_name: Miller, Tim B.
last_name: Miller
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Gabriel
full_name: Brammer, Gabriel
last_name: Brammer
- first_name: Claudia D.P.
full_name: Lagos, Claudia D.P.
last_name: Lagos
- first_name: Katherine E.
full_name: Whitaker, Katherine E.
last_name: Whitaker
- first_name: Christina C.
full_name: Williams, Christina C.
last_name: Williams
- first_name: Josephine F.W.
full_name: Baggen, Josephine F.W.
last_name: Baggen
- first_name: Rachel
full_name: Bezanson, Rachel
last_name: Bezanson
- first_name: Leindert A.
full_name: Boogaard, Leindert A.
last_name: Boogaard
- first_name: Nikko J.
full_name: Cleri, Nikko J.
last_name: Cleri
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Michaela
full_name: Hirschmann, Michaela
last_name: Hirschmann
- first_name: Raphael E.
full_name: Hviding, Raphael E.
last_name: Hviding
- first_name: Adarsh
full_name: Kuruvanthodi, Adarsh
last_name: Kuruvanthodi
- first_name: Ivo
full_name: Labbé, Ivo
last_name: Labbé
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Michael V.
full_name: Maseda, Michael V.
last_name: Maseda
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Ian
full_name: Mcconachie, Ian
last_name: Mcconachie
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: Guido
full_name: Roberts-Borsani, Guido
last_name: Roberts-Borsani
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Katherine A.
full_name: Suess, Katherine A.
last_name: Suess
- first_name: Francesco
full_name: Valentino, Francesco
last_name: Valentino
- first_name: Pieter
full_name: Van Dokkum, Pieter
last_name: Van Dokkum
- first_name: Bingjie
full_name: Wang, Bingjie
last_name: Wang
citation:
ama: Weibel A, De Graaff A, Setton DJ, et al. RUBIES reveals a massive quiescent
galaxy at z = 7.3. The Astrophysical Journal. 2025;983(1). doi:10.3847/1538-4357/adab7a
apa: Weibel, A., De Graaff, A., Setton, D. J., Miller, T. B., Oesch, P. A., Brammer,
G., … Wang, B. (2025). RUBIES reveals a massive quiescent galaxy at z = 7.3. The
Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/adab7a
chicago: Weibel, Andrea, Anna De Graaff, David J. Setton, Tim B. Miller, Pascal
A. Oesch, Gabriel Brammer, Claudia D.P. Lagos, et al. “RUBIES Reveals a Massive
Quiescent Galaxy at z = 7.3.” The Astrophysical Journal. IOP Publishing,
2025. https://doi.org/10.3847/1538-4357/adab7a.
ieee: A. Weibel et al., “RUBIES reveals a massive quiescent galaxy at z =
7.3,” The Astrophysical Journal, vol. 983, no. 1. IOP Publishing, 2025.
ista: Weibel A, De Graaff A, Setton DJ, Miller TB, Oesch PA, Brammer G, Lagos CDP,
Whitaker KE, Williams CC, Baggen JFW, Bezanson R, Boogaard LA, Cleri NJ, Greene
JE, Hirschmann M, Hviding RE, Kuruvanthodi A, Labbé I, Leja J, Maseda MV, Matthee
JJ, Mcconachie I, Naidu RP, Roberts-Borsani G, Schaerer D, Suess KA, Valentino
F, Van Dokkum P, Wang B. 2025. RUBIES reveals a massive quiescent galaxy at z
= 7.3. The Astrophysical Journal. 983(1), 11.
mla: Weibel, Andrea, et al. “RUBIES Reveals a Massive Quiescent Galaxy at z = 7.3.”
The Astrophysical Journal, vol. 983, no. 1, 11, IOP Publishing, 2025, doi:10.3847/1538-4357/adab7a.
short: A. Weibel, A. De Graaff, D.J. Setton, T.B. Miller, P.A. Oesch, G. Brammer,
C.D.P. Lagos, K.E. Whitaker, C.C. Williams, J.F.W. Baggen, R. Bezanson, L.A. Boogaard,
N.J. Cleri, J.E. Greene, M. Hirschmann, R.E. Hviding, A. Kuruvanthodi, I. Labbé,
J. Leja, M.V. Maseda, J.J. Matthee, I. Mcconachie, R.P. Naidu, G. Roberts-Borsani,
D. Schaerer, K.A. Suess, F. Valentino, P. Van Dokkum, B. Wang, The Astrophysical
Journal 983 (2025).
date_created: 2025-04-20T22:01:28Z
date_published: 2025-04-10T00:00:00Z
date_updated: 2026-02-16T12:42:28Z
day: '10'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/adab7a
external_id:
arxiv:
- '2409.03829'
isi:
- '001457334900001'
file:
- access_level: open_access
checksum: a1132e0b18bb643f9a32674c6694375a
content_type: application/pdf
creator: dernst
date_created: 2025-04-22T09:08:17Z
date_updated: 2025-04-22T09:08:17Z
file_id: '19605'
file_name: 2025_AstrophysicalJour_Weibel.pdf
file_size: 1964589
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intvolume: ' 983'
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language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: RUBIES reveals a massive quiescent galaxy at z = 7.3
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 983
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '19699'
abstract:
- lang: eng
text: We demonstrate that gas disks around binary systems might deliver gas to the
binary components only when the circumbinary disk is relatively warm. We present
new grid-based hydrodynamics simulations, performed with the binary on the grid
and a locally isothermal equation of state, in which the binary is seen to functionally
"stop accreting" if the orbital Mach number in the disk exceeds a threshold value
of about 40. Above this threshold, the disk continues to extract angular momentum
from the binary orbit, but it delivers very little mass to the black holes and
instead piles up mass in a ring surrounding the binary. This ring will eventually
become viscously relaxed and deliver mass to the binary at the large-scale inflow
rate. However, we show that the timescale for such relaxation can far exceed the
implied binary lifetime. We demonstrate that the ability of a binary–disk system
to equilibrate is dependent on the efficiency at which accretion streams deposit
mass onto the binary, which, in turn is highly sensitive to the thermodynamic
conditions of the inner disk. If disks around massive black hole binaries do operate
in such nonaccreting regimes, it suggests these systems may be dimmer than their
single black hole counterparts but could exhibit dramatic rebrightening after
the black holes inspiral and merge. This dimming begins in the UV/optical and
could completely choke high-energy emission, such that these systems would likely
be intrinsically X-ray weak with reddened continua, potentially resembling the
spectra of "little red dots" recently identified in JWST observations.
acknowledgement: C.T. sincerely thanks Daniel J. D'Orazio for useful and illuminating
discussions. This work was supported by the European Union's Horizon 2023 research
and innovation program under Marie Sklodowska-Curie grant agreement No. 101148364,
by Sapere Aude Starting grant No. 121587 through the Danish Independent Research
Fund, by the LISA Preparatory Science Program (LPS) through NASA grant 80NSSC24K0440,
and by NASA Astrophysics Theory Program (ATP) grant 80NSSC22K0822. Computation time
for this work was supported through the NYU IT High Performance Computing resources
as well as the Tycho supercomputer hosted at the SCIENCE HPC center at the University
of Copenhagen.
article_number: '144'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Christopher
full_name: Tiede, Christopher
last_name: Tiede
- first_name: Jonathan
full_name: Zrake, Jonathan
last_name: Zrake
- first_name: Andrew
full_name: Macfadyen, Andrew
last_name: Macfadyen
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
orcid: 0000-0003-3633-5403
citation:
ama: Tiede C, Zrake J, Macfadyen A, Haiman Z. Suppressed accretion onto massive
black hole binaries surrounded by thin disks. The Astrophysical Journal.
2025;984(2). doi:10.3847/1538-4357/adc727
apa: Tiede, C., Zrake, J., Macfadyen, A., & Haiman, Z. (2025). Suppressed accretion
onto massive black hole binaries surrounded by thin disks. The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/adc727
chicago: Tiede, Christopher, Jonathan Zrake, Andrew Macfadyen, and Zoltán Haiman.
“Suppressed Accretion onto Massive Black Hole Binaries Surrounded by Thin Disks.”
The Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/adc727.
ieee: C. Tiede, J. Zrake, A. Macfadyen, and Z. Haiman, “Suppressed accretion onto
massive black hole binaries surrounded by thin disks,” The Astrophysical Journal,
vol. 984, no. 2. IOP Publishing, 2025.
ista: Tiede C, Zrake J, Macfadyen A, Haiman Z. 2025. Suppressed accretion onto massive
black hole binaries surrounded by thin disks. The Astrophysical Journal. 984(2),
144.
mla: Tiede, Christopher, et al. “Suppressed Accretion onto Massive Black Hole Binaries
Surrounded by Thin Disks.” The Astrophysical Journal, vol. 984, no. 2,
144, IOP Publishing, 2025, doi:10.3847/1538-4357/adc727.
short: C. Tiede, J. Zrake, A. Macfadyen, Z. Haiman, The Astrophysical Journal 984
(2025).
date_created: 2025-05-18T22:02:49Z
date_published: 2025-05-09T00:00:00Z
date_updated: 2026-02-16T12:42:56Z
day: '09'
ddc:
- '520'
department:
- _id: ZoHa
doi: 10.3847/1538-4357/adc727
external_id:
arxiv:
- '2410.03830'
isi:
- '001483889000001'
file:
- access_level: open_access
checksum: 0d4c57ee944599c0789f3db467c5ca2f
content_type: application/pdf
creator: dernst
date_created: 2025-05-19T07:20:30Z
date_updated: 2025-05-19T07:20:30Z
file_id: '19708'
file_name: 2025_AstrophysicalJour_Tiede.pdf
file_size: 1058601
relation: main_file
success: 1
file_date_updated: 2025-05-19T07:20:30Z
has_accepted_license: '1'
intvolume: ' 984'
isi: 1
issue: '2'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Suppressed accretion onto massive black hole binaries surrounded by thin disks
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 984
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '19700'
abstract:
- lang: eng
text: The JWST discovery of "little red dots" (LRDs) is reshaping our picture of
the early Universe, yet the physical mechanisms driving their compact size and
UV-optical colors remain elusive. Here, we report an unusually bright LRD (zspec
= 3.1) observed as part of the RUBIES program. This LRD exhibits broad emission
lines (FWHM ∼ 4000 km s−1), a blue UV continuum, a clear Balmer break, and a red
continuum sampled out to rest-frame 4 μm with MIRI. We develop a new joint galaxy
and active galactic nucleus (AGN) model within the Prospector Bayesian inference
framework and perform spectrophotometric modeling using NIRCam, MIRI, and NIRSpec/Prism
observations. Our fiducial model reveals a M* ∼ 109 M⊙ galaxy alongside a dust-reddened
AGN driving the optical emission. Explaining the rest-frame optical color as a
reddened AGN requires AV ≳ 3, suggesting that a great majority of the accretion
disk energy is reradiated as dust emission. Yet, despite clear AGN signatures,
we find a surprising lack of hot torus emission, which implies that either the
dust emission in this object must be cold, or the red continuum must instead be
driven by a massive, evolved stellar population of the host galaxy—seemingly inconsistent
with the high-EW broad lines (Hα rest-frame EW ∼ 800 Å). The widths and luminosities
of Pa-β, Pa-δ, Pa-γ, and Hα imply a modest black hole mass of MBH ∼ 108 M⊙. Additionally,
we identify a narrow blueshifted He i λ 1.083 μm absorption feature in NIRSpec/G395M
spectra, signaling an ionized outflow with kinetic energy up to ∼1% the luminosity
of the AGN. The low redshift of RUBIES-BLAGN-1, combined with the depth and richness
of the JWST imaging and spectroscopic observations, provides a unique opportunity
to build a physical model for these so-far mysterious LRDs, which may prove to
be a crucial phase in the early formation of massive galaxies and their supermassive
black holes.
acknowledgement: 'B.W. and J.L. acknowledge support from JWST-GO-04233.009-A. R.L.D.
is supported by the Australian Research Council through the Discovery Early Career
Researcher Award (DECRA) Fellowship DE240100136 funded by the Australian Government.
T.B.M. was supported by a CIERA postdoctoral fellowship. The Cosmic Dawn Center
is funded by the Danish National Research Foundation (DNRF) under grant #140. This
research was supported by the International Space Science Institute (ISSI) in Bern,
through ISSI International Team project #562 (First Light at Cosmic Dawn: Exploiting
the James Webb Space Telescope Revolution). The JWST data presented in this article
were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space
Telescope Science Institute. The specific observations analyzed here can be accessed
via DOI:10.17909/c3t4-9p39. Computations for this research were performed on the
Pennsylvania State University''s Institute for Computational and Data Sciences''
Roar supercomputer. This publication made use of the NASA Astrophysical Data System
for bibliographic information.'
article_number: '121'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Bingjie
full_name: Wang, Bingjie
last_name: Wang
- first_name: Anna
full_name: De Graaff, Anna
last_name: De Graaff
- first_name: Rebecca L.
full_name: Davies, Rebecca L.
last_name: Davies
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Gabriel B.
full_name: Brammer, Gabriel B.
last_name: Brammer
- first_name: Andy D.
full_name: Goulding, Andy D.
last_name: Goulding
- first_name: Tim B.
full_name: Miller, Tim B.
last_name: Miller
- first_name: Katherine A.
full_name: Suess, Katherine A.
last_name: Suess
- first_name: Andrea
full_name: Weibel, Andrea
last_name: Weibel
- first_name: Christina C.
full_name: Williams, Christina C.
last_name: Williams
- first_name: Rachel
full_name: Bezanson, Rachel
last_name: Bezanson
- first_name: Leindert A.
full_name: Boogaard, Leindert A.
last_name: Boogaard
- first_name: Nikko J.
full_name: Cleri, Nikko J.
last_name: Cleri
- first_name: Michaela
full_name: Hirschmann, Michaela
last_name: Hirschmann
- first_name: Harley
full_name: Katz, Harley
last_name: Katz
- first_name: Ivo
full_name: Labbé, Ivo
last_name: Labbé
- first_name: Michael V.
full_name: Maseda, Michael V.
last_name: Maseda
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Ian
full_name: Mcconachie, Ian
last_name: Mcconachie
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Hans Walter
full_name: Rix, Hans Walter
last_name: Rix
- first_name: David J.
full_name: Setton, David J.
last_name: Setton
- first_name: Katherine E.
full_name: Whitaker, Katherine E.
last_name: Whitaker
citation:
ama: 'Wang B, De Graaff A, Davies RL, et al. RUBIES: JWST/NIRSpec confirmation of
an infrared-luminous, broad-line Little Red Dot with an ionized outflow. The
Astrophysical Journal. 2025;984(2). doi:10.3847/1538-4357/adc1ca'
apa: 'Wang, B., De Graaff, A., Davies, R. L., Greene, J. E., Leja, J., Brammer,
G. B., … Whitaker, K. E. (2025). RUBIES: JWST/NIRSpec confirmation of an infrared-luminous,
broad-line Little Red Dot with an ionized outflow. The Astrophysical Journal.
IOP Publishing. https://doi.org/10.3847/1538-4357/adc1ca'
chicago: 'Wang, Bingjie, Anna De Graaff, Rebecca L. Davies, Jenny E. Greene, Joel
Leja, Gabriel B. Brammer, Andy D. Goulding, et al. “RUBIES: JWST/NIRSpec Confirmation
of an Infrared-Luminous, Broad-Line Little Red Dot with an Ionized Outflow.” The
Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/adc1ca.'
ieee: 'B. Wang et al., “RUBIES: JWST/NIRSpec confirmation of an infrared-luminous,
broad-line Little Red Dot with an ionized outflow,” The Astrophysical Journal,
vol. 984, no. 2. IOP Publishing, 2025.'
ista: 'Wang B, De Graaff A, Davies RL, Greene JE, Leja J, Brammer GB, Goulding AD,
Miller TB, Suess KA, Weibel A, Williams CC, Bezanson R, Boogaard LA, Cleri NJ,
Hirschmann M, Katz H, Labbé I, Maseda MV, Matthee JJ, Mcconachie I, Naidu RP,
Oesch PA, Rix HW, Setton DJ, Whitaker KE. 2025. RUBIES: JWST/NIRSpec confirmation
of an infrared-luminous, broad-line Little Red Dot with an ionized outflow. The
Astrophysical Journal. 984(2), 121.'
mla: 'Wang, Bingjie, et al. “RUBIES: JWST/NIRSpec Confirmation of an Infrared-Luminous,
Broad-Line Little Red Dot with an Ionized Outflow.” The Astrophysical Journal,
vol. 984, no. 2, 121, IOP Publishing, 2025, doi:10.3847/1538-4357/adc1ca.'
short: B. Wang, A. De Graaff, R.L. Davies, J.E. Greene, J. Leja, G.B. Brammer, A.D.
Goulding, T.B. Miller, K.A. Suess, A. Weibel, C.C. Williams, R. Bezanson, L.A.
Boogaard, N.J. Cleri, M. Hirschmann, H. Katz, I. Labbé, M.V. Maseda, J.J. Matthee,
I. Mcconachie, R.P. Naidu, P.A. Oesch, H.W. Rix, D.J. Setton, K.E. Whitaker, The
Astrophysical Journal 984 (2025).
date_created: 2025-05-18T22:02:49Z
date_published: 2025-05-09T00:00:00Z
date_updated: 2026-02-16T12:42:43Z
day: '09'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/adc1ca
external_id:
arxiv:
- '2403.02304'
isi:
- '001481589300001'
file:
- access_level: open_access
checksum: 1a9ff4516d11808bc6947744473c9fc2
content_type: application/pdf
creator: dernst
date_created: 2025-05-19T07:08:39Z
date_updated: 2025-05-19T07:08:39Z
file_id: '19707'
file_name: 2025_AstrophysicalJour_Wang.pdf
file_size: 3522072
relation: main_file
success: 1
file_date_updated: 2025-05-19T07:08:39Z
has_accepted_license: '1'
intvolume: ' 984'
isi: 1
issue: '2'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'RUBIES: JWST/NIRSpec confirmation of an infrared-luminous, broad-line Little
Red Dot with an ionized outflow'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 984
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '20217'
abstract:
- lang: eng
text: "We present Virgil, a Mid-Infrared Instrument (MIRI) extremely red object
detected with the F1000W filter as part of the MIRI Deep Imaging Survey observations
of the Hubble Ultra Deep Field. Virgil is an Lyα emitter (LAE) at zspec = 6.6312
± 0.0019 (from the Very Large Telescope/MUSE) with a rest-frame UV-to-optical
spectral energy distribution (SED) typical of LAEs at similar redshifts. However,
MIRI observations reveal an unexpected extremely red color at rest-frame near-infrared
(NIR) wavelengths, F444W − F1000W = 2.33 ± 0.06. Such a steep\r\nrise in the NIR,
completely missed without MIRI imaging, is poorly reproduced by models including
only stellar populations and hints toward the presence of an active galactic nucleus,
although alternative explanations such as extreme dust obscuration and strong
nebular continuum and emission lines contribution due to young stellar ages cannot
be completely ruled out. According to the shape of its overall SED, Virgil belongs
to the recently discovered\r\npopulation of little red dots but displays an extended
rest-frame UV-optical wavelength morphology following a 2DSérsic profile with
an average index of n = 0.93+0.85_0.31 and re = 0.49+0.05_0.11 pkpc. Only at
MIRI wavelengths, Virgil is unresolved due to the coarser point-spread function.
This discovery demonstrates the crucial importance of deep MIRI surveys to reveal
the true nature and properties of high-z galaxies that otherwise would be misinterpreted
and raises the question of how common Virgil-like objects could be in the early
Universe."
acknowledgement: "The authors thank R. Cooper, G. Yang, V. Kokorev, D. Wen, C. Williams,
and H. Übler for useful discussions and comments.\r\nE.I. and K.I.C. acknowledge
funding from the Netherlands Research School for Astronomy (NOVA). K.I.C. acknowledges
funding from the Dutch Research Council (NWO) through the award of the Vici grant
VI.C.212.036. A.A.-H. acknowledges support from grant PID2021-124665NB-I00 funded
by MCIN/AEI/10.13039/ 501100011033 and by “ERDF A way of making Europe.” P.G.P.-G.
acknowledges support from grant PID2022-139567NB-I00 funded by the Spanish Ministerio
de Ciencia e Innovación MCIN/AEI/10.13039/501100011033, FEDER Una manera de hacer
Europa. J.A.-M., A.C.-G., and L.C. acknowledge support by grant PIB2021-127718NB-100
from the Spanish Ministry of Science and Innovation/State Agency of Research MCIN/AEI/10.13039/501100011033
and by “ERDF A way of making Europe.” L.C. thanks the support from the Cosmic Dawn
Center received during visits to DAWN as an international associate. L.C. acknowledges
support by grants PIB2021-127718NB-100 and PID2022-139567NB-I00 from the Spanish
Ministry of Science and Innovation/State Agency of Research MCIN/AEI/10.13039/501100011033
and by “ERDF A way of making Europe.” T.R.G. acknowledges support from the Carlsberg
Foundation (grant No. CF20-0534). S.G. acknowledges financial support from the Cosmic
Dawn Center (DAWN), funded by the Danish National Research Foundation (DNRF) under
grant No. 140. This work was supported by research grants (VIL16599, VIL54489) from
VILLUM FONDEN. J.P.P. and T.V.T. acknowledge financial support from the UK Science
and Technology Facilities Council and the UK Space Agency.\r\n\r\nThis work is based
on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data
were obtained from the MAST at the Space Telescope Science Institute, which is operated
by the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS 5-03127 for JWST. These observations are associated with programs GO #1963,
GO #1895, and GTO #1283. The authors acknowledge the team led by co-PIs: C. Williams,
M. Maseda, and S. Tacchella, and PI P. Oesch, for developing their respective observing
programs with a zero-exclusive-access period. Also based on observations made with
the NASA/ESA HST obtained from the Space Telescope Science Institute, which is operated
by the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS 5-26555. The work presented here is the effort of the entire MIRI team, and
the enthusiasm within the MIRI partnership is a significant factor in its success.
MIRI draws on the scientific and technical expertise of the following organizations:
Ames Research Center, USA; Airbus Defence and Space, UK; CEA-Irfu, Saclay, France;
Centre Spatial de Liège, Belgium; Consejo Superior de Investigaciones Científicas,
Spain; Carl Zeiss Optronics, Germany; Chalmers University of Technology, Sweden;
Danish Space Research Institute, Denmark; Dublin Institute for Advanced Studies,
Ireland; European Space Agency, Netherlands; ETCA, Belgium; ETH Zurich, Switzerland;
Goddard Space Flight Center, USA; Institute d’Astrophysique Spatiale, France; Instituto
Nacional de Técnica Aeroespacial, Spain; Institute for Astronomy, Edinburgh, UK;
Jet Propulsion Laboratory, USA; Laboratoire d’Astrophysique de Marseille (LAM),
France; Leiden University, Netherlands; Lockheed Advanced Technology Center (USA);
NOVA Opt-IR group at Dwingeloo, Netherlands; Northrop Grumman, USA; Max-Planck Institut
für Astronomie (MPIA), Heidelberg, Germany; Laboratoire d’Etudes Spatiales et d’Instrumentation
en Astrophysique (LESIA), France; Paul Scherrer Institut, Switzerland; Raytheon
Vision Systems, USA; RUAG Aerospace, Switzerland; Rutherford Appleton Laboratory
(RAL Space), UK; Space Telescope Science Institute, USA; Toegepast-Natuurwetenschappelijk
Onderzoek (TNO-TPD), Netherlands; UK Astronomy Technology Centre, UK; University
College London, UK; University of Amsterdam, Netherlands; University of Arizona,
USA; University of Cardiff, UK; University of Cologne, Germany; University of Ghent;
University of Groningen, Netherlands; University of Leicester, UK; University of
Leuven, Belgium; University of Stockholm, Sweden; Utah State University, USA.\r\nFor
the purpose of open access, the author has applied a Creative Commons Attribution
(CC BY) licence to the Author Accepted Manuscript version arising from this submission."
article_number: '160'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Edoardo
full_name: Iani, Edoardo
id: 4053390a-6b68-11ef-9828-a3b8adef8d0a
last_name: Iani
orcid: 0000-0001-8386-3546
- first_name: Pierluigi
full_name: Rinaldi, Pierluigi
last_name: Rinaldi
- first_name: Karina I.
full_name: Caputi, Karina I.
last_name: Caputi
- first_name: Marianna
full_name: Annunziatella, Marianna
last_name: Annunziatella
- first_name: Danial
full_name: Langeroodi, Danial
last_name: Langeroodi
- first_name: Jens
full_name: Melinder, Jens
last_name: Melinder
- first_name: Pablo G.
full_name: Pérez-González, Pablo G.
last_name: Pérez-González
- first_name: Javier
full_name: Álvarez-Márquez, Javier
last_name: Álvarez-Márquez
- first_name: Leindert A.
full_name: Boogaard, Leindert A.
last_name: Boogaard
- first_name: Sarah E.I.
full_name: Bosman, Sarah E.I.
last_name: Bosman
- first_name: Luca
full_name: Costantin, Luca
last_name: Costantin
- first_name: Thibaud
full_name: Moutard, Thibaud
last_name: Moutard
- first_name: Luis
full_name: Colina, Luis
last_name: Colina
- first_name: Göran
full_name: Östlin, Göran
last_name: Östlin
- first_name: Thomas R.
full_name: Greve, Thomas R.
last_name: Greve
- first_name: Gillian
full_name: Wright, Gillian
last_name: Wright
- first_name: Almudena
full_name: Alonso-Herrero, Almudena
last_name: Alonso-Herrero
- first_name: Arjan
full_name: Bik, Arjan
last_name: Bik
- first_name: Steven
full_name: Gillman, Steven
last_name: Gillman
- first_name: Alejandro
full_name: Crespo Gómez, Alejandro
last_name: Crespo Gómez
- first_name: Jens
full_name: Hjorth, Jens
last_name: Hjorth
- first_name: Sarah
full_name: Kendrew, Sarah
last_name: Kendrew
- first_name: Alvaro
full_name: Labiano, Alvaro
last_name: Labiano
- first_name: John P.
full_name: Pye, John P.
last_name: Pye
- first_name: Tuomo V.
full_name: Tikkanen, Tuomo V.
last_name: Tikkanen
- first_name: Fabian
full_name: Walter, Fabian
last_name: Walter
- first_name: Manuel
full_name: Güdel, Manuel
last_name: Güdel
- first_name: Thomas
full_name: Henning, Thomas
last_name: Henning
- first_name: Paul P.
full_name: Van Der Werf, Paul P.
last_name: Van Der Werf
citation:
ama: 'Iani E, Rinaldi P, Caputi KI, et al. MIDIS: MIRI uncovers Virgil, the first
Little Red Dot with clear detection of its host galaxy at z ≃ 6.6. The Astrophysical
Journal. 2025;989(2). doi:10.3847/1538-4357/ade5a6'
apa: 'Iani, E., Rinaldi, P., Caputi, K. I., Annunziatella, M., Langeroodi, D., Melinder,
J., … Van Der Werf, P. P. (2025). MIDIS: MIRI uncovers Virgil, the first Little
Red Dot with clear detection of its host galaxy at z ≃ 6.6. The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ade5a6'
chicago: 'Iani, Edoardo, Pierluigi Rinaldi, Karina I. Caputi, Marianna Annunziatella,
Danial Langeroodi, Jens Melinder, Pablo G. Pérez-González, et al. “MIDIS: MIRI
Uncovers Virgil, the First Little Red Dot with Clear Detection of Its Host Galaxy
at z ≃ 6.6.” The Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/ade5a6.'
ieee: 'E. Iani et al., “MIDIS: MIRI uncovers Virgil, the first Little Red
Dot with clear detection of its host galaxy at z ≃ 6.6,” The Astrophysical
Journal, vol. 989, no. 2. IOP Publishing, 2025.'
ista: 'Iani E, Rinaldi P, Caputi KI, Annunziatella M, Langeroodi D, Melinder J,
Pérez-González PG, Álvarez-Márquez J, Boogaard LA, Bosman SEI, Costantin L, Moutard
T, Colina L, Östlin G, Greve TR, Wright G, Alonso-Herrero A, Bik A, Gillman S,
Crespo Gómez A, Hjorth J, Kendrew S, Labiano A, Pye JP, Tikkanen TV, Walter F,
Güdel M, Henning T, Van Der Werf PP. 2025. MIDIS: MIRI uncovers Virgil, the first
Little Red Dot with clear detection of its host galaxy at z ≃ 6.6. The Astrophysical
Journal. 989(2), 160.'
mla: 'Iani, Edoardo, et al. “MIDIS: MIRI Uncovers Virgil, the First Little Red Dot
with Clear Detection of Its Host Galaxy at z ≃ 6.6.” The Astrophysical Journal,
vol. 989, no. 2, 160, IOP Publishing, 2025, doi:10.3847/1538-4357/ade5a6.'
short: E. Iani, P. Rinaldi, K.I. Caputi, M. Annunziatella, D. Langeroodi, J. Melinder,
P.G. Pérez-González, J. Álvarez-Márquez, L.A. Boogaard, S.E.I. Bosman, L. Costantin,
T. Moutard, L. Colina, G. Östlin, T.R. Greve, G. Wright, A. Alonso-Herrero, A.
Bik, S. Gillman, A. Crespo Gómez, J. Hjorth, S. Kendrew, A. Labiano, J.P. Pye,
T.V. Tikkanen, F. Walter, M. Güdel, T. Henning, P.P. Van Der Werf, The Astrophysical
Journal 989 (2025).
date_created: 2025-08-24T22:01:29Z
date_published: 2025-08-20T00:00:00Z
date_updated: 2026-02-16T12:43:12Z
day: '20'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ade5a6
external_id:
arxiv:
- '2406.18207'
isi:
- '001548132000001'
file:
- access_level: open_access
checksum: 92196e8352dddb1f305c253da1996ab6
content_type: application/pdf
creator: dernst
date_created: 2025-09-02T06:40:23Z
date_updated: 2025-09-02T06:40:23Z
file_id: '20268'
file_name: 2025_AstrophysicalJour_Iani.pdf
file_size: 5474992
relation: main_file
success: 1
file_date_updated: 2025-09-02T06:40:23Z
has_accepted_license: '1'
intvolume: ' 989'
isi: 1
issue: '2'
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'MIDIS: MIRI uncovers Virgil, the first Little Red Dot with clear detection
of its host galaxy at z ≃ 6.6'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 989
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '20586'
abstract:
- lang: eng
text: We present the discovery of deep, irregular, periodic transits toward the
white dwarf ZTF J1944+4557 using follow-up time-series photometry and spectroscopy
from Palomar, Keck, McDonald, Perkins, and Lowell observatories. We find a predominant
period of 4.9704 hr, consistent with an orbit near the Roche limit of the white
dwarf, with individual dips over 30% deep and lasting between 15 and 40 minutes.
Similar to the first known white dwarf with transiting debris, WD 1145+017, the
transit events are well-defined with prominent out-of-transit phases where the
white dwarf appears unobscured. Spectroscopy concurrent with transit photometry
reveals that the average Ca K equivalent width remains constant in and out of
transit. The broadening observed in several absorption features cannot be reproduced
by synthetic photospheric models, suggesting the presence of circumstellar gas.
Simultaneous g + r- and g + i-band light curves from the CHIMERA instrument reveal
no color dependence to the transit depths, requiring transiting dust grains to
have sizes s ≳ 0.2 μm. The transit morphologies appear to be constantly changing
at a rate faster than the orbital period. Overall transit activity varies in the
system, with transit features completely disappearing during the seven months
between our 2023 and 2024 observing seasons and then reappearing in 2025 March,
still repeating at 4.9704 hr. Our observations of the complete cessation and resumption
of transit activity provide a novel laboratory for constraining the evolution
of disrupted debris and processes like disk exhaustion and replenishment timescales
at white dwarfs.
acknowledgement: "We first extend our gratitude to our anonymous referee, whose careful
review and recommendations enhanced this manuscript. In fruitful conversations and
correspondence with Tim Cunningham, Jay Farihi, Jim Fuller, Philip Muirhead, Saul
Rappaport, Siyi Xu (许偲艺), and Nadia Zakamska, we found guidance that improved our
interpretation of these results. We are deeply grateful for the observing support
by John Kuehne at McDonald Observatory and Colt Pauley at the Perkins Telescope
Observatory. This material is based upon work supported by the National Aeronautics
and Space Administration under grant No. 80NSSC23K1068 issued through the Science
Mission Directorate. J.A.G. is supported by the National Science Foundation Graduate
Research Fellowship Program under grant No. 2234657.\r\n\r\nThis worked is based
on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch
Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project.
ZTF is supported by the National Science Foundation under grants No. AST-1440341
and AST-2034437 and a collaboration including current partners Caltech, IPAC, the
Oskar Klein Center at Stockholm University, the University of Maryland, University
of California, Berkeley, the University of Wisconsin at Milwaukee, University of
Warwick, Ruhr University, Cornell University, Northwestern University and Drexel
University. Operations are conducted by COO, IPAC, and UW.\r\n\r\nSome of the data
presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit
organization operated as a scientific partnership among the California Institute
of Technology, the University of California, and the National Aeronautics and Space
Administration. The Observatory was made possible by the generous financial support
of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the
very significant cultural role and reverence that the summit of Maunakea has always
had within the Native Hawaiian community. We are most fortunate to have the opportunity
to conduct observations from this mountain.\r\n\r\nThis work has made use of data
from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia),
processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).
Funding for the DPAC has been provided by national institutions, in particular the
institutions participating in the Gaia Multilateral Agreement.\r\n\r\nThis publication
also makes use of data products from NEOWISE, which is a project of the Jet Propulsion
Laboratory/California Institute of Technology, funded by the Planetary Science Division
of the National Aeronautics and Space Administration.\r\n\r\nThis work is based
in part on observations made with the Spitzer Space Telescope, which was operated
by the Jet Propulsion Laboratory, California Institute of Technology under a contract
with NASA.\r\n\r\nThe Pan-STARRS1 Surveys (PS1) and the PS1 public science archive
have been made possible through contributions by the Institute for Astronomy, the
University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and
its participating institutes, the Max Planck Institute for Astronomy, Heidelberg
and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins
University, Durham University, the University of Edinburgh, the Queen’s University
Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory
Global Telescope Network Incorporated, the National Central University of Taiwan,
the Space Telescope Science Institute, the National Aeronautics and Space Administration
under grant No. NNX08AR22G issued through the Planetary Science Division of the
NASA Science Mission Directorate, the National Science Foundation grant No. AST-1238877,
the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National
Laboratory, and the Gordon and Betty Moore Foundation.\r\n\r\nThis research relied
upon the SIMBAD and VizieR databases operated by CDS (Strasbourg, France) and the
bibliographic resources of The SAO Astrophysics Data System.\r\n\r\nFacilities:
PO:1.2m - Palomar Observatory's 1.2 meter Samuel Oschin Telescope (Zwicky Transient
Facility) - , Hale (CHIMERA, DBSP), Struve - McDonald Observatory's 2.1m Otto Struve
Telescope(ProEM), Perkins - Lowell Observatory's 72in Perkins Telescope (PRISM),
LDT - (LMI), Keck:I - KECK I Telescope (LRIS), Gaia - , PS1 - Panoramic Survey Telescope
and Rapid Response System Telescope #1 (Pan-STARRS), Spitzer (IRAC) - , WISE - Wide-field
Infrared Survey Explorer.\r\n\r\nSoftware: Astropy (Astropy Collaboration et al.
2013, 2018, 2022), astroquery (A. Ginsburg et al. 2019), ccdproc (M. Craig et al.
2017), cuvarbase (J. Hoffman 2022), extinction (K. Barbary 2016), hipercam (V. S.
Dhillon et al. 2021), lmfit (M. Newville et al. 2014), matplotlib (J. D. Hunter
2007), numpy (C. R. Harris et al. 2020), pandas (The pandas Development Team 2025),
phot2lc (Z. Vanderbosch 2023), photutils (L. Bradley et al. 2024), Pyriod (K. Bell
2022), scipy (P. Virtanen et al. 2020)."
article_number: '167'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Joseph A.
full_name: Guidry, Joseph A.
last_name: Guidry
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
- first_name: J. J.
full_name: Hermes, J. J.
last_name: Hermes
- first_name: Dimitri
full_name: Veras, Dimitri
last_name: Veras
- first_name: Mark A.
full_name: Hollands, Mark A.
last_name: Hollands
- first_name: Soumyadeep
full_name: Bhattacharjee, Soumyadeep
last_name: Bhattacharjee
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Malia L.
full_name: Kao, Malia L.
last_name: Kao
- first_name: Lou Baya
full_name: Ould Rouis, Lou Baya
last_name: Ould Rouis
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Jan
full_name: Van Roestel, Jan
last_name: Van Roestel
citation:
ama: Guidry JA, Vanderbosch ZP, Hermes JJ, et al. Transiting planetary debris near
the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing. The
Astrophysical Journal. 2025;992(2). doi:10.3847/1538-4357/adfecb
apa: Guidry, J. A., Vanderbosch, Z. P., Hermes, J. J., Veras, D., Hollands, M. A.,
Bhattacharjee, S., … Van Roestel, J. (2025). Transiting planetary debris near
the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing. The
Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/adfecb
chicago: Guidry, Joseph A., Zachary P. Vanderbosch, J. J. Hermes, Dimitri Veras,
Mark A. Hollands, Soumyadeep Bhattacharjee, Ilaria Caiazzo, et al. “Transiting
Planetary Debris near the Roche Limit of a White Dwarf on a 4.97 Hr Orbit—and
Its Vanishing.” The Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/adfecb.
ieee: J. A. Guidry et al., “Transiting planetary debris near the Roche limit
of a white dwarf on a 4.97 hr orbit—and its vanishing,” The Astrophysical Journal,
vol. 992, no. 2. IOP Publishing, 2025.
ista: Guidry JA, Vanderbosch ZP, Hermes JJ, Veras D, Hollands MA, Bhattacharjee
S, Caiazzo I, El-Badry K, Kao ML, Ould Rouis LB, Rodriguez AC, Van Roestel J.
2025. Transiting planetary debris near the Roche limit of a white dwarf on a 4.97
hr orbit—and its vanishing. The Astrophysical Journal. 992(2), 167.
mla: Guidry, Joseph A., et al. “Transiting Planetary Debris near the Roche Limit
of a White Dwarf on a 4.97 Hr Orbit—and Its Vanishing.” The Astrophysical Journal,
vol. 992, no. 2, 167, IOP Publishing, 2025, doi:10.3847/1538-4357/adfecb.
short: J.A. Guidry, Z.P. Vanderbosch, J.J. Hermes, D. Veras, M.A. Hollands, S. Bhattacharjee,
I. Caiazzo, K. El-Badry, M.L. Kao, L.B. Ould Rouis, A.C. Rodriguez, J. Van Roestel,
The Astrophysical Journal 992 (2025).
date_created: 2025-11-02T23:01:33Z
date_published: 2025-10-20T00:00:00Z
date_updated: 2026-02-16T12:43:29Z
day: '20'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/adfecb
external_id:
arxiv:
- '2508.18348'
isi:
- '001592080300001'
file:
- access_level: open_access
checksum: 24892d1b5bfa1867eb0a353f10c31b82
content_type: application/pdf
creator: dernst
date_created: 2025-11-04T12:33:51Z
date_updated: 2025-11-04T12:33:51Z
file_id: '20601'
file_name: 2025_AstrophysicalJour_Guidry.pdf
file_size: 5323398
relation: main_file
success: 1
file_date_updated: 2025-11-04T12:33:51Z
has_accepted_license: '1'
intvolume: ' 992'
isi: 1
issue: '2'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Transiting planetary debris near the Roche limit of a white dwarf on a 4.97
hr orbit—and its vanishing
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 992
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21057'
abstract:
- lang: eng
text: Among the most puzzling early discoveries of JWST are “little red dots” (LRDs),
compact red sources that host broad Balmer emission lines, and in many cases exhibit
a “V-shaped” change in slope in the rest-optical. The physical properties of LRDs
currently have order-of-magnitude uncertainties, because models to explain the
continuum of these sources differ immensely. Here, we leverage the complete selection
of red sources in the RUBIES program, supplemented with public PRISM spectra,
to study the origin of this V shape. By fitting a broken power law with a flexible
inflection point, we find that a large fraction of red Hα emitters at 2 < z <
6 exhibit a strong change in slope, and that all strong inflections appear associated
with the Balmer limit (0.3645 μm). Using a simple model of a reddened active galactic
nucleus (AGN) with an unobscured scattered-light component, we demonstrate that
the observed V shape in LRDs is unlikely to occur at any specific wavelength if
the entire continuum is dominated by light from a power-law AGN continuum. In
contrast, models with an intrinsic feature at the Balmer limit, such as those
that are dominated by an evolved stellar population, can produce the observed
spectral shapes, provided that a reddened component picks up sufficiently redward
of the break. While no model can comfortably explain the full LRD spectral energy
distribution, the common inflection location suggests that a single component
consistently dominates the rest-frame UV optical in LRDs, and that this component
is associated with T ∼ 10^4 K hydrogen.
acknowledgement: "This work is based in part on observations made with the NASA/ESA/CSA
James Webb Space Telescope. The data were obtained from the Mikulski Archive for
Space Telescopes at the Space Telescope Science Institute, which is operated by
the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS 5-03127 for JWST. The specific observations analyzed can be accessed via DOI:
10.17909/0esg-h949. All of the data products presented herein were retrieved from
the Dawn JWST Archive (DJA). DJA is an initiative of the Cosmic Dawn Center, which
is funded by the Danish National Research Foundation under grant No. 140. We express
gratitude toward the members of the GTO, GO, and DDT teams, whose public data we
utilized in this work.\r\n\r\nSupport for this work was provided by The Brinson
Foundation through a Brinson Prize Fellowship grant. Support for program No. 4233
was provided by NASA through a grant from the Space Telescope Science Institute,
which is operated by the Association of Universities for Research in Astronomy,
Inc., under NASA contract NAS 5-03127. This research was supported by the International
Space Science Institute (ISSI) in Bern, through ISSI International Team project
No. 562. D.S. acknowledges helpful conversations with Xiaohui Fan and Jared Siegel
that contributed to the quality of this work, in addition to aesthetic sign-off
from Stephanie Permut on the colors of figures. T.B.M. was supported by a CIERA
fellowship. The work of CCW is supported by NOIRLab, which is managed by the Association
of Universities for Research in Astronomy (AURA) under a cooperative agreement with
the National Science Foundation."
article_number: '118'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: David J.
full_name: Setton, David J.
last_name: Setton
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Anna
full_name: de Graaff, Anna
last_name: de Graaff
- first_name: Yilun 逸伦
full_name: Ma, Yilun 逸伦
last_name: Ma
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Rachel
full_name: Bezanson, Rachel
last_name: Bezanson
- first_name: Leindert A.
full_name: Boogaard, Leindert A.
last_name: Boogaard
- first_name: Nikko J.
full_name: Cleri, Nikko J.
last_name: Cleri
- first_name: Harley
full_name: Katz, Harley
last_name: Katz
- first_name: Ivo
full_name: Labbe, Ivo
last_name: Labbe
- first_name: Michael V.
full_name: Maseda, Michael V.
last_name: Maseda
- first_name: Ian
full_name: McConachie, Ian
last_name: McConachie
- first_name: Tim B.
full_name: Miller, Tim B.
last_name: Miller
- first_name: Sedona H.
full_name: Price, Sedona H.
last_name: Price
- first_name: Katherine A.
full_name: Suess, Katherine A.
last_name: Suess
- first_name: Pieter
full_name: van Dokkum, Pieter
last_name: van Dokkum
- first_name: Bingjie 冰洁
full_name: Wang 王, Bingjie 冰洁
last_name: Wang 王
- first_name: Andrea
full_name: Weibel, Andrea
last_name: Weibel
- first_name: Katherine E.
full_name: Whitaker, Katherine E.
last_name: Whitaker
- first_name: Christina C.
full_name: Williams, Christina C.
last_name: Williams
citation:
ama: 'Setton DJ, Greene JE, de Graaff A, et al. Little Red Dots at an inflection
point: Ubiquitous v-shaped turnover consistently occurs at the Balmer limit. The
Astrophysical Journal. 2025;995(1). doi:10.3847/1538-4357/ae1500'
apa: 'Setton, D. J., Greene, J. E., de Graaff, A., Ma, Y. 逸伦, Leja, J., Matthee,
J. J., … Williams, C. C. (2025). Little Red Dots at an inflection point: Ubiquitous
v-shaped turnover consistently occurs at the Balmer limit. The Astrophysical
Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae1500'
chicago: 'Setton, David J., Jenny E. Greene, Anna de Graaff, Yilun 逸伦 Ma, Joel Leja,
Jorryt J Matthee, Rachel Bezanson, et al. “Little Red Dots at an Inflection Point:
Ubiquitous v-Shaped Turnover Consistently Occurs at the Balmer Limit.” The
Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/ae1500.'
ieee: 'D. J. Setton et al., “Little Red Dots at an inflection point: Ubiquitous
v-shaped turnover consistently occurs at the Balmer limit,” The Astrophysical
Journal, vol. 995, no. 1. IOP Publishing, 2025.'
ista: 'Setton DJ, Greene JE, de Graaff A, Ma Y逸伦, Leja J, Matthee JJ, Bezanson R,
Boogaard LA, Cleri NJ, Katz H, Labbe I, Maseda MV, McConachie I, Miller TB, Price
SH, Suess KA, van Dokkum P, Wang 王 B冰洁, Weibel A, Whitaker KE, Williams CC. 2025.
Little Red Dots at an inflection point: Ubiquitous v-shaped turnover consistently
occurs at the Balmer limit. The Astrophysical Journal. 995(1), 118.'
mla: 'Setton, David J., et al. “Little Red Dots at an Inflection Point: Ubiquitous
v-Shaped Turnover Consistently Occurs at the Balmer Limit.” The Astrophysical
Journal, vol. 995, no. 1, 118, IOP Publishing, 2025, doi:10.3847/1538-4357/ae1500.'
short: D.J. Setton, J.E. Greene, A. de Graaff, Y.逸伦 Ma, J. Leja, J.J. Matthee, R.
Bezanson, L.A. Boogaard, N.J. Cleri, H. Katz, I. Labbe, M.V. Maseda, I. McConachie,
T.B. Miller, S.H. Price, K.A. Suess, P. van Dokkum, B.冰洁 Wang 王, A. Weibel, K.E.
Whitaker, C.C. Williams, The Astrophysical Journal 995 (2025).
date_created: 2026-01-28T15:21:47Z
date_published: 2025-12-09T00:00:00Z
date_updated: 2026-02-09T06:41:48Z
day: '09'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae1500
external_id:
arxiv:
- '2411.03424'
file:
- access_level: open_access
checksum: 2a424eb43748a6370ff058c98adb15c6
content_type: application/pdf
creator: dernst
date_created: 2026-02-09T06:39:23Z
date_updated: 2026-02-09T06:39:23Z
file_id: '21163'
file_name: 2025_AstrophysicalJournal_Setton.pdf
file_size: 1989640
relation: main_file
success: 1
file_date_updated: 2026-02-09T06:39:23Z
has_accepted_license: '1'
intvolume: ' 995'
issue: '1'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Little Red Dots at an inflection point: Ubiquitous v-shaped turnover consistently
occurs at the Balmer limit'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 995
year: '2025'
...