---
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '21342'
abstract:
- lang: eng
text: "JWST has revealed a stunning population of bright galaxies at surprisingly
early epochs, z > 10,\r\nwhere few such sources were expected. Here we present
the most distant example of this class yet – MoM-z14, a luminous (MUV = −20.2)
source in the COSMOS legacy field at zspec = 14.44+0.02−0.02 that expands the
observational frontier to a mere 280 million years after the Big Bang. The redshift
is confirmed with NIRSpec/prism spectroscopy through a sharp Lyman-α break and
≈ 3σ detections of five rest-UV emission lines. The number density of bright zspec
≈ 14 − 15 sources implied by our “Mirage or Miracle” survey spanning ≈ 350 arcmin2
is > 100× larger (182+329 −105×) than pre-JWST consensus models. The high EWs
of UV lines (≈15−35˚A) signal a rising star-formation history, with a ≈10× increase
in the last 5 Myr (SFR5Myr/SFR50Myr = 9.9 +3.0 −5.8). The source is extremely
compact (circularized re = 74+15\r\n−12 pc), and yet elongated (b/a = 0.25+0.11−0.06),
suggesting an AGN is not the dominant source of UV light. The steep UV slope (β
= −2.5 +0.2 −0.2) implies negligible dust attenuation\r\nand a young stellar population.
The absence of a strong damping wing provides tentative evidence that the immediate
surroundings of MoM-z14 may be partially ionized at a redshift where virtually
every reionization model predicts a ≈ 100% neutral fraction. The nitrogen emission
and highly supersolar [N/C]> 1 hint at an abundance pattern similar to local globular
clusters that may have once hosted luminous supermassive stars. Since this abundance
pattern is also common among the most ancient stars born in the Milky Way, we
may be directly witnessing the formation of such stars in dense clusters, connecting
galaxy evolution across the entire sweep of cosmic time. "
acknowledgement: "We thank the two anonymous referees for their insightful comments
that have strengthened this work. “Mirage or Miracle” is but the latest link in
a long chain of surveys that have built COSMOS into a premier extragalactic legacy
field. We are thankful to all the teams who have contributed to this legacy, particularly
those mentioned in §3 for leading recent JWST programs whose imaging\r\nwe have
incorporated in our analysis. We are grateful to Vasily Belokurov for help in compiling
the Milky Way reference sample featured in Fig 8. We thank Danielle Berg for sharing
a highly complete, highly decimalized NUV vacuum line list. We are grateful to our
program’s NIRSpec reviewer, Dan Coe, and program coordinator, Allison Vick, for
valuable input on our MSA design. We acknowledge illuminating conversations with
Risa Wechsler and Chao-Lin Kuo about early reionization. RPN thanks Neil Pappalardo
and Jane Pappalardo for their generous support of the MIT Pappalardo Fellowships
in Physics, and for their enthusiasm and encouragement for seeking galaxies at the
highest redshifts. RPN acknowledges funding from JWST program GO5224. Support for
this work 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.
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. Funded by
the European Union (ERC, AGENTS, 101076224 and HEAVYMETAL, 101071865). Views and
opinions expressed are however those of the author(s) only and do not necessarily
reflect those of\r\nthe European Union or the European Research Council. Neither
the European Union nor the granting authority can be held responsible for them.
The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation
under grant DNRF140. This work has also been supported by JSPS KAKENHI Grant Number
23H00131. HA acknowledges support from CNES, focused on the JWST mission, and the
Programme National Cosmology and Galaxies (PNCG)\r\nof CNRS/INSU with INP and IN2P3,
co-funded by CEA and CNES. HA is supported by the French National Research Agency
(ANR) under the project FIRSTGAL, grant number ANR-24-CE31-0838. SB is supported
by the UK Research and Innovation (UKRI) Future Leaders Fellowship [grant number
MR/V023381/1]. R.D. acknowledges support from the INAF GO 2022\r\ngrant “The birth
of the giants: JWST sheds light on the build-up of quasars at cosmic dawn” and by
the PRIN MUR “2022935STW”, RFF M4.C2.1.1, CUP J53D23001570006 and C53D23000950006.
Computations supporting this paper were run on MIT’s Engaging cluster. This publication
made use of the NASA Astrophysical Data System for bibliographic information. Some
of the data products presented herein were retrieved from the Dawn JWST Archive
(DJA). DJA is an initiative of the Cosmic Dawn Center (DAWN), which is funded by
the Danish National Research Foundation under grant DNRF140. Software used in developing
this work includes: matplotlib (Hunter 2007), jupyter (Kluyver et al. 2016), IPython
(P´erez & Granger 2007), numpy (Oliphant 2015), scipy (Virtanen et al. 2020), TOPCAT
(Taylor 2005), and Astropy (Astropy Collaboration et al. 2013).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\r\nTelescopes 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 # 5224."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- 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: Gabriel
full_name: Brammer, Gabriel
last_name: Brammer
- first_name: Andrea
full_name: Weibel, Andrea
last_name: Weibel
- first_name: Yijia
full_name: Li, Yijia
last_name: Li
- 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: John
full_name: Chisholm, John
last_name: Chisholm
- first_name: Clara L.
full_name: Pollock, Clara L.
last_name: Pollock
- first_name: Kasper E.
full_name: Heintz, Kasper E.
last_name: Heintz
- first_name: Benjamin D.
full_name: Johnson, Benjamin D.
last_name: Johnson
- first_name: Xuejian
full_name: Shen, Xuejian
last_name: Shen
- first_name: Raphael E.
full_name: Hviding, Raphael E.
last_name: Hviding
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Sandro
full_name: Tacchella, Sandro
last_name: Tacchella
- first_name: Arpita
full_name: Ganguly, Arpita
last_name: Ganguly
- first_name: Callum
full_name: Witten, Callum
last_name: Witten
- first_name: Hakim
full_name: Atek, Hakim
last_name: Atek
- first_name: Sirio
full_name: Belli, Sirio
last_name: Belli
- first_name: Sownak
full_name: Bose, Sownak
last_name: Bose
- first_name: Rychard
full_name: Bouwens, Rychard
last_name: Bouwens
- first_name: Pratika
full_name: Dayal, Pratika
last_name: Dayal
- first_name: Roberto
full_name: Decarli, Roberto
last_name: Decarli
- first_name: Anna
full_name: De Graaff, Anna
last_name: De Graaff
- first_name: Yoshinobu
full_name: Fudamoto, Yoshinobu
last_name: Fudamoto
- first_name: Emma
full_name: Giovinazzo, Emma
last_name: Giovinazzo
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Garth
full_name: Illingworth, Garth
last_name: Illingworth
- first_name: Akio K.
full_name: Inoue, Akio K.
last_name: Inoue
- first_name: Sarah G.
full_name: Kane, Sarah G.
last_name: Kane
- first_name: Ivo
full_name: Labbe, Ivo
last_name: Labbe
- first_name: Ecaterina
full_name: Leonova, Ecaterina
last_name: Leonova
- first_name: Rui
full_name: Marques-Chaves, Rui
last_name: Marques-Chaves
- first_name: Romain A.
full_name: Meyer, Romain A.
last_name: Meyer
- first_name: Erica J.
full_name: Nelson, Erica J.
last_name: Nelson
- first_name: Guido
full_name: Roberts-Borsani, Guido
last_name: Roberts-Borsani
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Robert A.
full_name: Simcoe, Robert A.
last_name: Simcoe
- first_name: Mauro
full_name: Stefanon, Mauro
last_name: Stefanon
- first_name: Yuma
full_name: Sugahara, Yuma
last_name: Sugahara
- first_name: Sune
full_name: Toft, Sune
last_name: Toft
- first_name: Arjen
full_name: Van Der Wel, Arjen
last_name: Van Der Wel
- first_name: Pieter
full_name: Van Dokkum, Pieter
last_name: Van Dokkum
- first_name: Fabian
full_name: Walter, Fabian
last_name: Walter
- first_name: Darach
full_name: Watson, Darach
last_name: Watson
- first_name: John R.
full_name: Weaver, John R.
last_name: Weaver
- first_name: Katherine E.
full_name: Whitaker, Katherine E.
last_name: Whitaker
citation:
ama: 'Naidu RP, Oesch PA, Brammer G, et al. A cosmic miracle: A remarkably luminous
galaxy at zspec = 14.44 confirmed with JWST. The Open Journal of Astrophysics.
2026;9. doi:10.33232/001c.156033'
apa: 'Naidu, R. P., Oesch, P. A., Brammer, G., Weibel, A., Li, Y., Matthee, J. J.,
… Whitaker, K. E. (2026). A cosmic miracle: A remarkably luminous galaxy at zspec
= 14.44 confirmed with JWST. The Open Journal of Astrophysics. Maynooth
Academic Publishing. https://doi.org/10.33232/001c.156033'
chicago: 'Naidu, Rohan P., Pascal A. Oesch, Gabriel Brammer, Andrea Weibel, Yijia
Li, Jorryt J Matthee, John Chisholm, et al. “A Cosmic Miracle: A Remarkably Luminous
Galaxy at Zspec = 14.44 Confirmed with JWST.” The Open Journal of Astrophysics.
Maynooth Academic Publishing, 2026. https://doi.org/10.33232/001c.156033.'
ieee: 'R. P. Naidu et al., “A cosmic miracle: A remarkably luminous galaxy
at zspec = 14.44 confirmed with JWST,” The Open Journal of Astrophysics,
vol. 9. Maynooth Academic Publishing, 2026.'
ista: 'Naidu RP, Oesch PA, Brammer G, Weibel A, Li Y, Matthee JJ, Chisholm J, Pollock
CL, Heintz KE, Johnson BD, Shen X, Hviding RE, Leja J, Tacchella S, Ganguly A,
Witten C, Atek H, Belli S, Bose S, Bouwens R, Dayal P, Decarli R, De Graaff A,
Fudamoto Y, Giovinazzo E, Greene JE, Illingworth G, Inoue AK, Kane SG, Labbe I,
Leonova E, Marques-Chaves R, Meyer RA, Nelson EJ, Roberts-Borsani G, Schaerer
D, Simcoe RA, Stefanon M, Sugahara Y, Toft S, Van Der Wel A, Van Dokkum P, Walter
F, Watson D, Weaver JR, Whitaker KE. 2026. A cosmic miracle: A remarkably luminous
galaxy at zspec = 14.44 confirmed with JWST. The Open Journal of Astrophysics.
9.'
mla: 'Naidu, Rohan P., et al. “A Cosmic Miracle: A Remarkably Luminous Galaxy at
Zspec = 14.44 Confirmed with JWST.” The Open Journal of Astrophysics, vol.
9, Maynooth Academic Publishing, 2026, doi:10.33232/001c.156033.'
short: R.P. Naidu, P.A. Oesch, G. Brammer, A. Weibel, Y. Li, J.J. Matthee, J. Chisholm,
C.L. Pollock, K.E. Heintz, B.D. Johnson, X. Shen, R.E. Hviding, J. Leja, S. Tacchella,
A. Ganguly, C. Witten, H. Atek, S. Belli, S. Bose, R. Bouwens, P. Dayal, R. Decarli,
A. De Graaff, Y. Fudamoto, E. Giovinazzo, J.E. Greene, G. Illingworth, A.K. Inoue,
S.G. Kane, I. Labbe, E. Leonova, R. Marques-Chaves, R.A. Meyer, E.J. Nelson, G.
Roberts-Borsani, D. Schaerer, R.A. Simcoe, M. Stefanon, Y. Sugahara, S. Toft,
A. Van Der Wel, P. Van Dokkum, F. Walter, D. Watson, J.R. Weaver, K.E. Whitaker,
The Open Journal of Astrophysics 9 (2026).
date_created: 2026-02-22T23:01:35Z
date_published: 2026-01-30T00:00:00Z
date_updated: 2026-06-16T10:47:41Z
day: '30'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.33232/001c.156033
external_id:
arxiv:
- '2505.11263'
fulldoi: https://doi.org/10.33232/001c.156033
has_accepted_license: '1'
intvolume: ' 9'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
main_file_link:
- open_access: '1'
url: https://doi.org/10.33232/001c.156033
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 Open Journal of Astrophysics
publication_identifier:
eissn:
- 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'A cosmic miracle: A remarkably luminous galaxy at zspec = 14.44 confirmed
with JWST'
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: 9
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '21934'
abstract:
- lang: eng
text: "An accurate characterisation of the physical properties of galaxies at cosmic
dawn is key to understanding\r\nthe origin of the high abundance of UV-bright
galaxies at z≳10. We exploit deep (9.1-hour exposure time)\r\nNIRSpec PRISM observations
of GHZ2 to constrain the sources of ionising radiation and the properties of the\r\ninterstellar
medium (ISM) in this bright, compact, and highly ionising galaxy at z=12.3. We
measure with\r\nhigh significance the prominent N IV, C IV, He II, O III, C III,
O II, and Ne III emission features previously\r\ndetected in shallower observations,
and confirm the detection of the N III] λ1750 multiplet, yielding tight\r\nconstraints
on the N/O ratio, which is found to be ≃2 times the solar value. We also detect
the Mg II λ2800,\r\n[Fe IV] λ2833 and Si II λ1812 doublets, the H8+HeI λλ3889
blend, and the Si IV+O IV] λλ1400 absorption\r\ncomplex. The O III λ3133 fluorescence
line is only detected in the first observing epoch, implying variability\r\non
a rest-frame time span of 19 days, strongly suggesting the presence of an active
nucleus. Combining the\r\nNIRSpec dataset with available optical and far-infrared
constraints from MIRI and ALMA, we show that the\r\nemission spectrum of GHZ2
cannot be reproduced by single-density spectro-photometric models, even under\r\nextreme
assumptions on the ionisation parameter and electron density. Multi-zone photoionisation
modelling\r\nperformed with the HOMERUN code demonstrates that star formation
must be occurring in a strongly stratified\r\nISM, where both low-/intermediate-density
gas and high-density regions (log(ne/cm−3\r\n) ≳ 4) coexist. The\r\nGHZ2 emission
landscape is consistent with either a composite star-formation plus AGN scenario,
or with\r\nstar formation occurring in a combination of radiation- and matter-bounded
regions. Purely radiation-bounded\r\nstellar models fail to reproduce the observed
He II emission, making an additional hard ionising component\r\nunavoidable."
acknowledgement: "We thank the referee for the constructive comments that\r\nhelped
us improve the manuscript. We thank S. Finkelstein,\r\nY. Harikane, C. Mason, and
D. Stark for the useful comments.\r\nWe thank Tony Roman (Program Coordinator) and
Glenn\r\nWahlgren (NIRSpec reviewer) for the assistance in the\r\npreparation of
GO-3073 observations. This work is based\r\non observations made with the NASA/ESA/CSA
James\r\nWebb Space Telescope (JWST). The JWST data presented in this article were
obtained from the Mikulski Archive for\r\nSpace Telescopes (MAST) at the Space Telescope
Science\r\nInstitute. The specific observations analysed are associated with program
JWST-GO-3073 and can be accessed\r\nvia https://doi.org/10.17909/4r6b-bx96 (first
pointing) and\r\nhttps://doi:10.17909/zq4g-r525 (second pointing). We\r\nacknowledge
financial support from NASA through grant\r\nJWST-ERS-1324 and JWST-GO-3073. Support
was also\r\nprovided by the PRIN 2022 MUR project 2022CB3PJ3 –\r\nFirst Light And
Galaxy aSsembly (FLAGS) funded by the\r\nEuropean Union – Next Generation EU, by
INAF GO Grant\r\n2024 ”Revealing the nature of bright galaxies at cosmic\r\ndawn
with deep JWST spectroscopy”, by INAF Mini-grant\r\n2022 “Reionization and Fundamental
Cosmology with\r\nHigh-Redshift Galaxies”, and by INAF Large Grant 2022\r\n“Extragalactic
Surveys with JWST”. L.N. acknowledges\r\nsupport from grant “Progetti per Avvio
alla Ricerca - Tipo\r\n1, Unveiling Cosmic Dawn: Galaxy Evolution with CAPERS” (AR1241906F947685).
EV acknowledges financial\r\nsupport through grants INAF GO Grant 2024 “Mapping
Star\r\nCluster Feedback in a Galaxy 450 Myr after the Big Bang”\r\nand by the European
Union – NextGenerationEU within\r\nPRIN 2022 project n.20229YBSAN - Globular clusters\r\nin
cosmological simulations and lensed fields: from their\r\nbirth to the present epoch.
AM acknowledges support\r\nfrom project PRIN-MUR project “PROMETEUS” financed\r\nby
the European Union - Next Generation EU, Mission 4\r\nComponent 1 CUP B53D2300475000.
AM acknowledges\r\nsupport from Ricerca Fondamentale INAF under Mini Grant\r\n2023
”Quantitative Spectroscopy of Ionized Nebulae and\r\nGalaxies (QSING)” and under
Data Analysis Grant 2024\r\n“Accurate measurements of metallicity in galaxies with
a new\r\napproach to photoionization modelling”."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: M.
full_name: Castellano, M.
last_name: Castellano
- first_name: L.
full_name: Napolitano, L.
last_name: Napolitano
- first_name: B.
full_name: Moreschini, B.
last_name: Moreschini
- first_name: A.
full_name: Calabrò, A.
last_name: Calabrò
- first_name: L.
full_name: Christensen, L.
last_name: Christensen
- first_name: M.
full_name: Llerena, M.
last_name: Llerena
- first_name: T. J.L.C.
full_name: Bakx, T. J.L.C.
last_name: Bakx
- first_name: F.
full_name: Belfiore, F.
last_name: Belfiore
- first_name: D.
full_name: Bevacqua, D.
last_name: Bevacqua
- first_name: M.
full_name: Dickinson, M.
last_name: Dickinson
- first_name: A.
full_name: Fontana, A.
last_name: Fontana
- first_name: G.
full_name: Gandolfi, G.
last_name: Gandolfi
- first_name: T.
full_name: Gasparetto, T.
last_name: Gasparetto
- first_name: A.
full_name: Marconi, A.
last_name: Marconi
- first_name: Sara
full_name: Mascia, Sara
id: edaf889c-c7cd-11ef-ab1b-bb28c431bd29
last_name: Mascia
- first_name: E.
full_name: Merlin, E.
last_name: Merlin
- first_name: T.
full_name: Morishita, T.
last_name: Morishita
- first_name: T.
full_name: Nanayakkara, T.
last_name: Nanayakkara
- first_name: D.
full_name: Paris, D.
last_name: Paris
- first_name: L.
full_name: Pentericci, L.
last_name: Pentericci
- first_name: B.
full_name: Pérez-Díaz, B.
last_name: Pérez-Díaz
- first_name: G.
full_name: Roberts-Borsani, G.
last_name: Roberts-Borsani
- first_name: S.
full_name: Rojas-Ruiz, S.
last_name: Rojas-Ruiz
- first_name: P.
full_name: Santini, P.
last_name: Santini
- first_name: T.
full_name: Treu, T.
last_name: Treu
- first_name: E.
full_name: Vanzella, E.
last_name: Vanzella
- first_name: B.
full_name: Vulcani, B.
last_name: Vulcani
- first_name: X.
full_name: Wang, X.
last_name: Wang
- first_name: I.
full_name: Yoon, I.
last_name: Yoon
- first_name: J.
full_name: Zavala, J.
last_name: Zavala
citation:
ama: Castellano M, Napolitano L, Moreschini B, et al. Investigating ionising sources
and the complex interstellar medium of GHZ2 at z=12.3. The Open Journal of
Astrophysics. 2026;9. doi:10.33232/001c.160281
apa: Castellano, M., Napolitano, L., Moreschini, B., Calabrò, A., Christensen, L.,
Llerena, M., … Zavala, J. (2026). Investigating ionising sources and the complex
interstellar medium of GHZ2 at z=12.3. The Open Journal of Astrophysics.
Maynooth Academic Publishing. https://doi.org/10.33232/001c.160281
chicago: Castellano, M., L. Napolitano, B. Moreschini, A. Calabrò, L. Christensen,
M. Llerena, T. J.L.C. Bakx, et al. “Investigating Ionising Sources and the Complex
Interstellar Medium of GHZ2 at Z=12.3.” The Open Journal of Astrophysics.
Maynooth Academic Publishing, 2026. https://doi.org/10.33232/001c.160281.
ieee: M. Castellano et al., “Investigating ionising sources and the complex
interstellar medium of GHZ2 at z=12.3,” The Open Journal of Astrophysics,
vol. 9. Maynooth Academic Publishing, 2026.
ista: Castellano M, Napolitano L, Moreschini B, Calabrò A, Christensen L, Llerena
M, Bakx TJLC, Belfiore F, Bevacqua D, Dickinson M, Fontana A, Gandolfi G, Gasparetto
T, Marconi A, Mascia S, Merlin E, Morishita T, Nanayakkara T, Paris D, Pentericci
L, Pérez-Díaz B, Roberts-Borsani G, Rojas-Ruiz S, Santini P, Treu T, Vanzella
E, Vulcani B, Wang X, Yoon I, Zavala J. 2026. Investigating ionising sources and
the complex interstellar medium of GHZ2 at z=12.3. The Open Journal of Astrophysics.
9.
mla: Castellano, M., et al. “Investigating Ionising Sources and the Complex Interstellar
Medium of GHZ2 at Z=12.3.” The Open Journal of Astrophysics, vol. 9, Maynooth
Academic Publishing, 2026, doi:10.33232/001c.160281.
short: M. Castellano, L. Napolitano, B. Moreschini, A. Calabrò, L. Christensen,
M. Llerena, T.J.L.C. Bakx, F. Belfiore, D. Bevacqua, M. Dickinson, A. Fontana,
G. Gandolfi, T. Gasparetto, A. Marconi, S. Mascia, E. Merlin, T. Morishita, T.
Nanayakkara, D. Paris, L. Pentericci, B. Pérez-Díaz, G. Roberts-Borsani, S. Rojas-Ruiz,
P. Santini, T. Treu, E. Vanzella, B. Vulcani, X. Wang, I. Yoon, J. Zavala, The
Open Journal of Astrophysics 9 (2026).
date_created: 2026-05-31T22:02:14Z
date_published: 2026-04-09T00:00:00Z
date_updated: 2026-06-02T06:39:53Z
day: '09'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.33232/001c.160281
external_id:
arxiv:
- '2512.08490'
file:
- access_level: open_access
checksum: ec33ca56b8836c61cb01e26893d43cbf
content_type: application/pdf
creator: dernst
date_created: 2026-06-02T06:38:59Z
date_updated: 2026-06-02T06:38:59Z
file_id: '21935'
file_name: 2026_OpenJourAstrophysics_Castellano.pdf
file_size: 4855934
relation: main_file
success: 1
file_date_updated: 2026-06-02T06:38:59Z
fulldoi: https://doi.org/10.33232/001c.160281
has_accepted_license: '1'
intvolume: ' 9'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
publication: The Open Journal of Astrophysics
publication_identifier:
eissn:
- 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Investigating ionising sources and the complex interstellar medium of GHZ2
at z=12.3
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: 9
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '21951'
abstract:
- lang: eng
text: "The central engines of Little Red Dots (LRDs) may be “black hole stars” (BH*s),
early stages of\r\nblack hole growth characterized by dense gas envelopes. So
far, the most direct evidence for BH*s\r\ncomes from a handful of sources where
the host galaxy is completely outshone as suggested by their\r\nremarkably steep
Balmer breaks. Here we present a novel scheme to disentangle BH*s from their\r\nhost
galaxies assuming that the [O III]5008˚A line arises exclusively from the host.
Using a sample\r\nof 98 LRDs (z ≈ 2 − 9) with high quality NIRSpec/PRISM spectra,
we demonstrate that the hostsubtracted median stack displays a Balmer break >
2× stronger than massive quiescent galaxies,\r\nwith the rest-optical continuum
resembling a blackbody-like SED (Teff ≈ 4050 K, log(Lbol) ≈ 43.9\r\nerg s−1\r\n,
Reff ≈ 1300 au). We measure a steep Balmer decrement (Hα/Hβ > 10) and numerous\r\ndensity-sensitive
features (e.g., Fe II, He I, O I). These are hallmark signatures of dense gas
envelopes,\r\nproviding population-level evidence that BH*s indeed power LRDs.
In the median LRD, BH*s account\r\nfor ∼ 20% of the UV emission, ∼ 50% at the
Balmer break, and ∼ 90% at wavelengths longer\r\nthan Hα with the remainder arising
from the host. BH*s preferentially reside in low-mass galaxies\r\n(M⋆ ≈ 108 M⊙)
undergoing recent starbursts, as evidenced by extreme emission line EWs (e.g.,\r\n[O
III]5008˚A≈ 1100˚A, C III]≈ 12˚A), thereby favoring BH* origins linked to star-formation.
We show\r\nV-shaped LRD selections are biased to high BH*/host fractions (≳ 60%
at 5500˚A) – less dominant\r\nBH*s may be powering JWST’s blue broad-line AGN.
We find BH*s are so commonplace and transient\r\n(duty cycle ∼ 1%, lifetime ∼
10 Myrs) that every massive black hole may have once shone as a BH*.\r\n"
acknowledgement: "We thank the two anonymous referees for their insightful comments
that have strengthened this work.\r\nWQS and RPN acknowledge funding from JWST programs
GO-3516, GO-5224, and the MIT Undergraduate\r\nResearch Opportunities Program (UROP).
Support for\r\nthis work was provided by NASA through the NASA\r\nHubble Fellowship
grant HST-HF2-51515.001-A awarded\r\nby the Space Telescope Science Institute, which
is operated by the Association of Universities for Research in\r\nAstronomy, Incorporated,
under NASA contract NAS5-\r\n26555. RPN thanks Neil Pappalardo and Jane Pappalardo
for their generous support of the MIT Pappalardo Fellowships in Physics, and for
their enthusiasm\r\nand encouragement for pursuing the earliest galaxies and\r\nblack
holes. JM and AT acknowledge funding from the\r\nEuropean Union (ERC, AGENTS, 101076224).
KEH\r\nacknowledges support from the Independent Research Fund Denmark (DFF) under
grant 5251-00009B and cofunding by the European Union (ERC, HEAVYMETAL,\r\n101071865).
Views and opinions expressed are, however,\r\nthose of the authors only and do not
necessarily reflect\r\nthose of the European Union or the European Research\r\nCouncil.
Neither the European Union nor the granting\r\nauthority can be held responsible
for them. REH acknowledges support by the German Aerospace Center\r\n(DLR) and the
Federal Ministry for Economic Affairs\r\nand Energy (BMWi) through program 50OR2403
‘RUBIES’.\r\nThe data products presented herein were retrieved\r\nfrom the Dawn
JWST Archive (DJA). DJA is an initiative of the Cosmic Dawn Center (DAWN), which
is\r\nfunded by the Danish National Research Foundation under grant DNRF140. This
work is based on observations\r\nmade with the NASA/ESA/CSA James Webb Space\r\nTelescope.
The data were obtained from the Mikulski Archive for Space Telescopes at the Space
Telescope\r\nScience Institute, which is operated by the Association\r\nof Universities
for Research in Astronomy, Inc., under\r\nNASA contract NAS 5-03127 for JWST. Support
for\r\nprograms #3516, #5224, #5664 was provided by NASA\r\nthrough grants from
the Space Telescope Science Institute, which is operated by the Association of Universities\r\nfor
Research in Astronomy, Inc., under NASA contract\r\nNAS 5-03127.\r\nThe spectra
used in this paper are associated with programs 1180 (D’Eugenio et al. 2025d), 1181
(PI: D. Eisenstein), 1208 (Willott et al. 2022), 1210 (PI: N. Luetzgendorf), 1211
(Maseda et al. 2024), 1212 - 1215 (PI: N.\r\nLuetzgendorf), 1228 (Luhman et al.
2024b), 1229 (Luhman et al. 2024a), 1286 (PI: N. Luetzgendorf), 1287 (PI:\r\nK.
Isaak), 1345 (Finkelstein et al. 2023), 1433 (Hsiao\r\net al. 2024), 1747 (PI: G.
Roberts-Borsani), 2028 (Wang\r\net al. 2024c), 2073 (PI: J. Hennawi), 2198 (Barrufet\r\net
al. 2025), 2282 (Bradley et al. 2023), 2561 (Bezanson\r\net al. 2024), 2565 (Nanayakkara
et al. 2025), 2640 (PI:\r\nW. Best), 2750 (Arrabal Haro et al. 2023), 2756 (Mascia
et al. 2024), 2767 (Williams et al. 2023b), 2770 (PI:\r\nM. McCaughrean), 3073 (Castellano
et al. 2024), 3215\r\n(Eisenstein et al. 2025), 4106 (PI: E. Nelson), 4233 (de\r\nGraaff
et al. 2025c), 4446 (Frye et al. 2024), 4557 (PI: H.\r\nYan), 5105 (Shen et al.
2024), 5224 (PIs: P.A. Oesch &\r\nR.P. Naidu), 6368 (PI: M. Dickinson), 6541 (DeCoursey\r\net
al. 2025), 6585 (PI: D. Coulter), 6642 (PI: J. Muzerolle\r\nPage), and FRESCO IFU
(Matthee et al. 2024; Torralba\r\net al. 2025b).\r\nSoftware used in developing
this work includes:\r\nmatplotlib (Hunter 2007), jupyter (Kluyver et al.\r\n2016),
IPython (P´erez & Granger 2007), numpy\r\n(Oliphant 2015), scipy (Virtanen et al.
2020), TOPCAT\r\n(Taylor 2005), Astropy (Astropy Collaboration et al.\r\n2013),
msaexp (Brammer 2023)."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Wendy Q.
full_name: Sun, Wendy Q.
last_name: Sun
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- 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: Anna
full_name: De Graaff, Anna
last_name: De Graaff
- first_name: John
full_name: Chisholm, John
last_name: Chisholm
- first_name: Jenny E.
full_name: Greene, Jenny E.
last_name: Greene
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Alberto
full_name: Torralba Torregrosa, Alberto
id: 018f0249-0e87-11f0-b167-cbce08fbd541
last_name: Torralba Torregrosa
orcid: 0000-0001-5586-6950
- first_name: Raphael E.
full_name: Hviding, Raphael E.
last_name: Hviding
- first_name: Gabriel
full_name: Brammer, Gabriel
last_name: Brammer
- first_name: Robert A.
full_name: Simcoe, Robert A.
last_name: Simcoe
- first_name: Sownak
full_name: Bose, Sownak
last_name: Bose
- first_name: Rychard
full_name: Bouwens, Rychard
last_name: Bouwens
- first_name: Pratika
full_name: Dayal, Pratika
last_name: Dayal
- first_name: Anna Christina
full_name: Eilers, Anna Christina
last_name: Eilers
- first_name: Qinyue
full_name: Fei, Qinyue
last_name: Fei
- first_name: Lukas J.
full_name: Furtak, Lukas J.
last_name: Furtak
- first_name: Rashmi
full_name: Gottumukkala, Rashmi
last_name: Gottumukkala
- first_name: Andy
full_name: Goulding, Andy
last_name: Goulding
- first_name: Kasper E.
full_name: Heintz, Kasper E.
last_name: Heintz
- first_name: Michaela
full_name: Hirschmann, Michaela
last_name: Hirschmann
- first_name: Vasily
full_name: Kokorev, Vasily
last_name: Kokorev
- first_name: Joel
full_name: Leja, Joel
last_name: Leja
- first_name: Zhaoran
full_name: Liu, Zhaoran
last_name: Liu
- first_name: Priyamvada
full_name: Natarajan, Priyamvada
last_name: Natarajan
- first_name: Andrew D.
full_name: Santarelli, Andrew D.
last_name: Santarelli
- first_name: David J.
full_name: Setton, David J.
last_name: Setton
- first_name: Aaron
full_name: Smith, Aaron
last_name: Smith
- first_name: Sandro
full_name: Tacchella, Sandro
last_name: Tacchella
- first_name: Marta
full_name: Volonteri, Marta
last_name: Volonteri
- first_name: Fabian
full_name: Walter, Fabian
last_name: Walter
- first_name: Andrea
full_name: Weibel, Andrea
last_name: Weibel
- first_name: Christina C.
full_name: Williams, Christina C.
last_name: Williams
citation:
ama: 'Sun WQ, Naidu RP, Matthee JJ, et al. Little Red Dot - Host Galaxy = Black
Hole Star: A gas-enshrouded heart at the center of every Little Red Dot. The
Open Journal of Astrophysics. 2026;9. doi:10.33232/001c.162505'
apa: 'Sun, W. Q., Naidu, R. P., Matthee, J. J., De Graaff, A., Chisholm, J., Greene,
J. E., … Williams, C. C. (2026). Little Red Dot - Host Galaxy = Black Hole Star:
A gas-enshrouded heart at the center of every Little Red Dot. The Open Journal
of Astrophysics. Maynooth Academic Publishing. https://doi.org/10.33232/001c.162505'
chicago: 'Sun, Wendy Q., Rohan P. Naidu, Jorryt J Matthee, Anna De Graaff, John
Chisholm, Jenny E. Greene, Pascal A. Oesch, et al. “Little Red Dot - Host Galaxy
= Black Hole Star: A Gas-Enshrouded Heart at the Center of Every Little Red Dot.”
The Open Journal of Astrophysics. Maynooth Academic Publishing, 2026. https://doi.org/10.33232/001c.162505.'
ieee: 'W. Q. Sun et al., “Little Red Dot - Host Galaxy = Black Hole Star:
A gas-enshrouded heart at the center of every Little Red Dot,” The Open Journal
of Astrophysics, vol. 9. Maynooth Academic Publishing, 2026.'
ista: 'Sun WQ, Naidu RP, Matthee JJ, De Graaff A, Chisholm J, Greene JE, Oesch PA,
Torralba Torregrosa A, Hviding RE, Brammer G, Simcoe RA, Bose S, Bouwens R, Dayal
P, Eilers AC, Fei Q, Furtak LJ, Gottumukkala R, Goulding A, Heintz KE, Hirschmann
M, Kokorev V, Leja J, Liu Z, Natarajan P, Santarelli AD, Setton DJ, Smith A, Tacchella
S, Volonteri M, Walter F, Weibel A, Williams CC. 2026. Little Red Dot - Host Galaxy
= Black Hole Star: A gas-enshrouded heart at the center of every Little Red Dot.
The Open Journal of Astrophysics. 9.'
mla: 'Sun, Wendy Q., et al. “Little Red Dot - Host Galaxy = Black Hole Star: A Gas-Enshrouded
Heart at the Center of Every Little Red Dot.” The Open Journal of Astrophysics,
vol. 9, Maynooth Academic Publishing, 2026, doi:10.33232/001c.162505.'
short: W.Q. Sun, R.P. Naidu, J.J. Matthee, A. De Graaff, J. Chisholm, J.E. Greene,
P.A. Oesch, A. Torralba Torregrosa, R.E. Hviding, G. Brammer, R.A. Simcoe, S.
Bose, R. Bouwens, P. Dayal, A.C. Eilers, Q. Fei, L.J. Furtak, R. Gottumukkala,
A. Goulding, K.E. Heintz, M. Hirschmann, V. Kokorev, J. Leja, Z. Liu, P. Natarajan,
A.D. Santarelli, D.J. Setton, A. Smith, S. Tacchella, M. Volonteri, F. Walter,
A. Weibel, C.C. Williams, The Open Journal of Astrophysics 9 (2026).
date_created: 2026-06-07T22:01:36Z
date_published: 2026-05-25T00:00:00Z
date_updated: 2026-06-08T08:25:40Z
day: '25'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.33232/001c.162505
external_id:
arxiv:
- '2601.20929'
file:
- access_level: open_access
checksum: 33c4a444f7c37b3f47ecbd53eb187c1b
content_type: application/pdf
creator: dernst
date_created: 2026-06-08T08:23:37Z
date_updated: 2026-06-08T08:23:37Z
file_id: '21952'
file_name: 2026_OpenJourAstrophysics_Sun.pdf
file_size: 7591188
relation: main_file
success: 1
file_date_updated: 2026-06-08T08:23:37Z
fulldoi: https://doi.org/10.33232/001c.162505
has_accepted_license: '1'
intvolume: ' 9'
language:
- iso: eng
month: '05'
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 Open Journal of Astrophysics
publication_identifier:
eissn:
- 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Little Red Dot - Host Galaxy = Black Hole Star: A gas-enshrouded heart at
the center of every Little Red Dot'
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: 9
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '22270'
abstract:
- lang: eng
text: "The explosion of a white dwarf (WD) in a close binary can launch a surviving
runaway star at\r\nvelocities of ≳ 1000 km s−1\r\n. Such runaways provide a direct
probe of thermonuclear supernovae (SNe)\r\nin double-degenerate binaries. Several
candidate runaways are known, but their evolutionary states\r\nand the demographics
of the broader population are uncertain. To enable robust population inference,\r\nwe
carry out a systematic survey for hypervelocity runaways with a simple selection
function, selecting\r\ncandidates based on large Gaia-inferred tangential velocities
and blue colors. We classify 100% of the\r\nresulting 92 candidates using a combination
of spectroscopic follow-up and archival data. The search\r\nyields ten suspected
D6\r\nstars and three LP 40-365 stars. Three D6\r\nstars are new discoveries,
including\r\ntwo hot (Teff ≳ 50,000 K) objects and one cool (Teff ≈ 7,000 K) object.
We forward-model our survey\r\nunder several proposed D6\r\nstar evolutionary
models, coupling each to a Galactic model and the survey\r\nselection function.
No single model reproduces the observed diversity of D6\r\nstars, which likely
reflects\r\na range of remnant masses, ages, and heating mechanisms. Models in
which runaway companions\r\nare heated by SN shocks alone are too faint and short-lived
to explain most of the observed sample,\r\nwhile fully reheated models are too
luminous and long-lived. Models with intermediate heating,\r\nas occurs in some
simulations of violent mergers and partially disrupted remnants, best match the\r\nobserved
magnitude, distance, and kinematic-age distributions. The inferred D6\r\nstar
birth rate is\r\nmodel dependent, but the models that best match the observed
population require rates of only a\r\nfew percent of the Galactic SN Ia rate,
perhaps implying that most SNe Ia result from WD binaries\r\nin which both components
explode. If most SNe Ia do produce surviving runaways, these must be\r\nfainter
or shorter-lived than the currently known runaways."
acknowledgement: "We thank Lars Bildsten, Evan Bauer, Ruediger Pakmor, Jim Fuller,
Logan Proust, Abinaya Rajamuthukumar, and Stephan Geier for useful discussion related
to\r\nthis work.\r\nThis work was supported by NSF grants AST-2508988\r\nand AST-2205631,
NASA/ESA Hubble Space Telescope\r\nprogram No. 17441, and Scialog grant #SA-LSST-2024-\r\n114c
from the Research Corporation for Science Advancement. The Kavli Institute for Theoretical
Physics\r\n(KITP) hosted the program, “White Dwarfs as Probes of\r\nthe Evolution
of Planets, Stars, the Milky Way, and the\r\nExpanding Universe,” during which this
project was initiated. This research was supported in part by the U.S.\r\nNational
Science Foundation (NSF) under grants PHY1748958. This research benefited from discussions
that\r\nwere funded by the Gordon and Betty Moore Foundation\r\nthrough Grant GBMF5076.\r\nWe
thank the staffs of the various observatories at\r\nwhich data were obtained. This
work is partially based\r\non observations obtained at the Southern Astrophysical
Research (SOAR) telescope, which is a joint project\r\nof the Minist´erio da Ciˆencia,
Tecnologia e Inova¸c˜oes\r\n(MCTI/LNA) do Brasil, the US National Science Foundation’s
NOIRLab, the University of North Carolina\r\nat Chapel Hill (UNC), and Michigan
State University\r\n(MSU). Some of the data presented herein were obtained\r\nat
the W. M. Keck Observatory, which is operated as a\r\nscientific partnership among
the California Institute of\r\nTechnology, the University of California, and NASA;
the observatory was made possible by the generous financial\r\nsupport of the W.
M. Keck Foundation.\r\nThis research has made use of the Keck Observatory\r\nArchive
(KOA), which is operated by the W. M. Keck\r\nObservatory and the NASA Exoplanet
Science Institute\r\n(NExScI), under contract with the National Aeronautics\r\nand
Space Administration.\r\nThis work has made use of data from the\r\nEuropean Space
Agency (ESA) mission Gaia\r\n(https://www.cosmos.esa.int/gaia), processed\r\nby
the Gaia Data Processing and Analysis Consortium\r\n(DPAC, https://www.cosmos.esa.int/web/gaia/\r\ndpac/consortium).
Funding for the DPAC has been\r\nprovided by national institutions, in particular
the\r\ninstitutions participating in the Gaia Multilateral\r\nAgreement."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Klaus
full_name: Werner, Klaus
last_name: Werner
- first_name: Ken J.
full_name: Shen, Ken J.
last_name: Shen
- first_name: Jay
full_name: Strader, Jay
last_name: Strader
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Jiwon Jesse
full_name: Han, Jiwon Jesse
last_name: Han
- first_name: Vedant
full_name: Chandra, Vedant
last_name: Chandra
- first_name: Laura
full_name: Chomiuk, Laura
last_name: Chomiuk
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
- first_name: Lisa
full_name: Blomberg, Lisa
last_name: Blomberg
- first_name: Natsuko
full_name: Yamaguchi, Natsuko
last_name: Yamaguchi
- first_name: Pranav
full_name: Nagarajan, Pranav
last_name: Nagarajan
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
- first_name: Hila
full_name: Glanz, Hila
last_name: Glanz
- first_name: Tin Long Sunny
full_name: Wong, Tin Long Sunny
last_name: Wong
- first_name: Aakash
full_name: Bhat, Aakash
last_name: Bhat
- first_name: Mark A.
full_name: Hollands, Mark A.
last_name: Hollands
citation:
ama: El-Badry K, Werner K, Shen KJ, et al. A systematic survey for hypervelocity
runaways from thermonuclear supernovae. The Open Journal of Astrophysics.
2026;9. doi:10.33232/001c.164326
apa: El-Badry, K., Werner, K., Shen, K. J., Strader, J., Rodriguez, A. C., Han,
J. J., … Hollands, M. A. (2026). A systematic survey for hypervelocity runaways
from thermonuclear supernovae. The Open Journal of Astrophysics. Maynooth
Academic Publishing. https://doi.org/10.33232/001c.164326
chicago: El-Badry, Kareem, Klaus Werner, Ken J. Shen, Jay Strader, Antonio C. Rodriguez,
Jiwon Jesse Han, Vedant Chandra, et al. “A Systematic Survey for Hypervelocity
Runaways from Thermonuclear Supernovae.” The Open Journal of Astrophysics.
Maynooth Academic Publishing, 2026. https://doi.org/10.33232/001c.164326.
ieee: K. El-Badry et al., “A systematic survey for hypervelocity runaways
from thermonuclear supernovae,” The Open Journal of Astrophysics, vol.
9. Maynooth Academic Publishing, 2026.
ista: El-Badry K, Werner K, Shen KJ, Strader J, Rodriguez AC, Han JJ, Chandra V,
Chomiuk L, Vanderbosch ZP, Blomberg L, Yamaguchi N, Nagarajan P, Caiazzo I, van
Roestel JC, Glanz H, Wong TLS, Bhat A, Hollands MA. 2026. A systematic survey
for hypervelocity runaways from thermonuclear supernovae. The Open Journal of
Astrophysics. 9.
mla: El-Badry, Kareem, et al. “A Systematic Survey for Hypervelocity Runaways from
Thermonuclear Supernovae.” The Open Journal of Astrophysics, vol. 9, Maynooth
Academic Publishing, 2026, doi:10.33232/001c.164326.
short: K. El-Badry, K. Werner, K.J. Shen, J. Strader, A.C. Rodriguez, J.J. Han,
V. Chandra, L. Chomiuk, Z.P. Vanderbosch, L. Blomberg, N. Yamaguchi, P. Nagarajan,
I. Caiazzo, J.C. van Roestel, H. Glanz, T.L.S. Wong, A. Bhat, M.A. Hollands, The
Open Journal of Astrophysics 9 (2026).
das_tickbox: '1'
dataavailabilitystatement: "We thank the staffs of the various observatories at\r\nwhich
data were obtained. This work is partially based\r\non observations obtained at
the Southern Astrophysical Research (SOAR) telescope, which is a joint project\r\nof
the Minist´erio da Ciˆencia, Tecnologia e Inova¸c˜oes\r\n(MCTI/LNA) do Brasil, the
US National Science Foundation’s NOIRLab, the University of North Carolina\r\nat
Chapel Hill (UNC), and Michigan State University\r\n(MSU). Some of the data presented
herein were obtained\r\nat the W. M. Keck Observatory, which is operated as a\r\nscientific
partnership among the California Institute of\r\nTechnology, the University of California,
and NASA; the\r\nobservatory was made possible by the generous financial\r\nsupport
of the W. M. Keck Foundation.\r\nThis research has made use of the Keck Observatory\r\nArchive
(KOA), which is operated by the W. M. Keck\r\nObservatory and the NASA Exoplanet
Science Institute\r\n(NExScI), under contract with the National Aeronautics\r\nand
Space Administration.\r\nThis work has made use of data from the\r\nEuropean Space
Agency (ESA) mission Gaia\r\n(https://www.cosmos.esa.int/gaia), processed\r\nby
the Gaia Data Processing and Analysis Consortium\r\n(DPAC, https://www.cosmos.esa.int/web/gaia/\r\ndpac/consortium).
Funding for the DPAC has been\r\nprovided by national institutions, in particular
the\r\ninstitutions participating in the Gaia Multilateral\r\nAgreement."
date_created: 2026-07-12T22:02:19Z
date_published: 2026-06-30T00:00:00Z
date_updated: 2026-07-13T09:09:34Z
day: '30'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.33232/001c.164326
external_id:
arxiv:
- '2606.11293'
file:
- access_level: open_access
checksum: 6320fd19e5ea3399f332be5aab022736
content_type: application/pdf
creator: dernst
date_created: 2026-07-13T09:05:36Z
date_updated: 2026-07-13T09:05:36Z
file_id: '22282'
file_name: 2026_OpenJourAstrophysics_ElBadry.pdf
file_size: 1994596
relation: main_file
success: 1
file_date_updated: 2026-07-13T09:05:36Z
fulldoi: https://doi.org/10.33232/001c.164326
has_accepted_license: '1'
intvolume: ' 9'
keyword:
- white dwarfs
- 'binaries: close'
- 'stars: chemically peculiar'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
publication: The Open Journal of Astrophysics
publication_identifier:
eissn:
- 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: no
title: A systematic survey for hypervelocity runaways from thermonuclear supernovae
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: 9
year: '2026'
...
---
OA_place: publisher
OA_type: diamond
_id: '22928'
abstract:
- lang: eng
text: "We present deep ALMA Band 7 observations of the [O iii] 88 µm line and underlying
dust continuum\r\nemission in four UV-bright, gravitationally lensed (magnification
µ = 1.4 − 3.8), JWST-selected\r\ngalaxies at z = 8.5 − 10.3, with observed magnitudes
−22.5 ≲ MUV ≲ −20.5. [O iii] 88 µm is\r\nconfidently detected in UNCOVER-10646
at z = 8.5080 ± 0.0011 (15σ) and DHZ1 at z = 9.3113 ±\r\n0.0006 (6σ), with both
being intrinsically luminous systems [L[O iii] = (1.1− 1.6) ×109 L⊙] that follow\r\nthe
local [O iii]-SFR relation. [O iii] 88 µm remains undetected in the two z > 10
targets, including in\r\nthe z = 10.07 X-ray AGN UHZ1, where we obtain a deep
limit of L[O iii] < 6 × 107 L⊙. Dust emission\r\nis not detected in any individual
source nor in a stack (< 3σ). The high S/N [O iii] 88 µm detection\r\nin UNCOVER-10646
uniquely reveals an additional broad component (FWHM = 1366+473\r\n−329 km/s;\r\n∆BIC
≈ 20) indicative of an ionized outflow. We infer a high outflow rate of M˙\r\nout
= 128+80\r\n−46 M⊙ yr−1\r\n,\r\ncorresponding to a mass loading factor η = M˙\r\nout/SFR
= 2.9\r\n+1.8\r\n−1.0\r\nthat matches or exceeds theoretical\r\npredictions and
JWST-based studies of ionized outflows at high redshift. While high-resolution
ALMA\r\nfollow-up is required to confirm and spatially resolve the outflow, this
first systematic study at z > 8\r\nhighlights the unique diagnostic power of [O
iii] 88 µm in characterizing galaxies in the early Universe."
acknowledgement: "We thank the referee for their valuable and constructive comments
that improved this work. We also thank Javier Alvarez-M´arquez for useful discussions
´\r\nabout the MIRI observations of UHZ1 and UNCOVER37126. HSBA gratefully acknowledges
support from\r\nAcademia Sinica through grant AS-PD-1141-M01-2. MA\r\nis supported
by FONDECYT grant number 1252054,\r\nand gratefully acknowledges support from ANID
Basal\r\nProject FB210003 and ANID MILENIO NCN2024 112.\r\nAKI acknowledges support
from KAKENHI Grant No.\r\n23H00131. NW was supported by the GACR EXPRO\r\ngrant
No. 21-13491X.\r\nThis paper makes use of the following ALMA data:\r\nADS/JAO.ALMA#2024.1.00440.S,\r\nADS/JAO.ALMA#2024.1.01197.S\r\nALMA
is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan),
together with\r\nNRC (Canada), MOST and ASIAA (Taiwan), and KASI\r\n(Republic of
Korea), in cooperation with the Republic\r\nof Chile. The Joint ALMA Observatory
is operated by\r\nESO, AUI/NRAO and NAOJ."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Hiddo S.B.
full_name: Algera, Hiddo S.B.
last_name: Algera
- first_name: John R.
full_name: Weaver, John R.
last_name: Weaver
- first_name: Tom J.L.C.
full_name: Bakx, Tom J.L.C.
last_name: Bakx
- first_name: Manuel
full_name: Aravena, Manuel
last_name: Aravena
- first_name: Rychard J.
full_name: Bouwens, Rychard J.
last_name: Bouwens
- first_name: Karin
full_name: Cescon, Karin
last_name: Cescon
- first_name: Chian Chou
full_name: Chen, Chian Chou
last_name: Chen
- first_name: Elisabete
full_name: Da Cunha, Elisabete
last_name: Da Cunha
- first_name: Pratika
full_name: Dayal, Pratika
last_name: Dayal
- first_name: Andreas
full_name: Faisst, Andreas
last_name: Faisst
- first_name: Andrea
full_name: Ferrara, Andrea
last_name: Ferrara
- first_name: Seiji
full_name: Fujimoto, Seiji
last_name: Fujimoto
- first_name: Takuya
full_name: Hashimoto, Takuya
last_name: Hashimoto
- first_name: Kasper
full_name: Heintz, Kasper
last_name: Heintz
- first_name: Rodrigo
full_name: Herrera-Camus, Rodrigo
last_name: Herrera-Camus
- first_name: Jacqueline
full_name: Hodge, Jacqueline
last_name: Hodge
- first_name: Hanae
full_name: Inami, Hanae
last_name: Inami
- first_name: Akio K.
full_name: Inoue, Akio K.
last_name: Inoue
- 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: Romain
full_name: Meyer, Romain
last_name: Meyer
- first_name: Shoichiro
full_name: Mizukoshi, Shoichiro
last_name: Mizukoshi
- first_name: Chayan
full_name: Mondal, Chayan
last_name: Mondal
- first_name: Themiya
full_name: Nanayakkara, Themiya
last_name: Nanayakkara
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Andrea
full_name: Pallottini, Andrea
last_name: Pallottini
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
- first_name: Lucie E.
full_name: Rowland, Lucie E.
last_name: Rowland
- first_name: Sander
full_name: Schouws, Sander
last_name: Schouws
- first_name: Renske
full_name: Smit, Renske
last_name: Smit
- first_name: Laura
full_name: Sommovigo, Laura
last_name: Sommovigo
- first_name: Daniel P.
full_name: Stark, Daniel P.
last_name: Stark
- first_name: Yuma
full_name: Sugahara, Yuma
last_name: Sugahara
- first_name: Livia
full_name: Vallini, Livia
last_name: Vallini
- first_name: Bovornpratch
full_name: Vijarnwannaluk, Bovornpratch
last_name: Vijarnwannaluk
- first_name: Paul
full_name: Van Der Werf, Paul
last_name: Van Der Werf
- first_name: Norbert
full_name: Werner, Norbert
last_name: Werner
- first_name: Joris
full_name: Witstok, Joris
last_name: Witstok
- first_name: Mengyuan
full_name: Xiao, Mengyuan
last_name: Xiao
citation:
ama: 'Algera HSB, Weaver JR, Bakx TJLC, et al. A first systematic study of [OIII]
88μm at z>8: two luminous oxygen lines and a powerful ionized outflow in the
first 600 million years. The Open Journal of Astrophysics. 2026;9. doi:10.33232/001c.165333'
apa: 'Algera, H. S. B., Weaver, J. R., Bakx, T. J. L. C., Aravena, M., Bouwens,
R. J., Cescon, K., … Xiao, M. (2026). A first systematic study of [OIII] 88μm
at z>8: two luminous oxygen lines and a powerful ionized outflow in the first
600 million years. The Open Journal of Astrophysics. Maynooth Academic
Publishing. https://doi.org/10.33232/001c.165333'
chicago: 'Algera, Hiddo S.B., John R. Weaver, Tom J.L.C. Bakx, Manuel Aravena, Rychard
J. Bouwens, Karin Cescon, Chian Chou Chen, et al. “A First Systematic Study of
[OIII] 88μm at Z>8: Two Luminous Oxygen Lines and a Powerful Ionized Outflow
in the First 600 Million Years.” The Open Journal of Astrophysics. Maynooth
Academic Publishing, 2026. https://doi.org/10.33232/001c.165333.'
ieee: 'H. S. B. Algera et al., “A first systematic study of [OIII] 88μm at
z>8: two luminous oxygen lines and a powerful ionized outflow in the first
600 million years,” The Open Journal of Astrophysics, vol. 9. Maynooth
Academic Publishing, 2026.'
ista: 'Algera HSB, Weaver JR, Bakx TJLC, Aravena M, Bouwens RJ, Cescon K, Chen CC,
Da Cunha E, Dayal P, Faisst A, Ferrara A, Fujimoto S, Hashimoto T, Heintz K, Herrera-Camus
R, Hodge J, Inami H, Inoue AK, Matthee JJ, Meyer R, Mizukoshi S, Mondal C, Nanayakkara
T, Oesch PA, Pallottini A, Röttgering H, Rowland LE, Schouws S, Smit R, Sommovigo
L, Stark DP, Sugahara Y, Vallini L, Vijarnwannaluk B, Van Der Werf P, Werner N,
Witstok J, Xiao M. 2026. A first systematic study of [OIII] 88μm at z>8: two
luminous oxygen lines and a powerful ionized outflow in the first 600 million
years. The Open Journal of Astrophysics. 9.'
mla: 'Algera, Hiddo S. B., et al. “A First Systematic Study of [OIII] 88μm at Z>8:
Two Luminous Oxygen Lines and a Powerful Ionized Outflow in the First 600 Million
Years.” The Open Journal of Astrophysics, vol. 9, Maynooth Academic Publishing,
2026, doi:10.33232/001c.165333.'
short: H.S.B. Algera, J.R. Weaver, T.J.L.C. Bakx, M. Aravena, R.J. Bouwens, K. Cescon,
C.C. Chen, E. Da Cunha, P. Dayal, A. Faisst, A. Ferrara, S. Fujimoto, T. Hashimoto,
K. Heintz, R. Herrera-Camus, J. Hodge, H. Inami, A.K. Inoue, J.J. Matthee, R.
Meyer, S. Mizukoshi, C. Mondal, T. Nanayakkara, P.A. Oesch, A. Pallottini, H.
Röttgering, L.E. Rowland, S. Schouws, R. Smit, L. Sommovigo, D.P. Stark, Y. Sugahara,
L. Vallini, B. Vijarnwannaluk, P. Van Der Werf, N. Werner, J. Witstok, M. Xiao,
The Open Journal of Astrophysics 9 (2026).
dataavailabilitystatement: "This paper makes use of the following ALMA data:\r\nADS/JAO.ALMA#2024.1.00440.S,\r\nADS/JAO.ALMA#2024.1.01197.S\r\nALMA
is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan),
together with\r\nNRC (Canada), MOST and ASIAA (Taiwan), and KASI\r\n(Republic of
Korea), in cooperation with the Republic\r\nof Chile. The Joint ALMA Observatory
is operated by\r\nESO, AUI/NRAO and NAOJ."
date_created: 2026-09-13T22:01:57Z
date_published: 2026-07-21T00:00:00Z
date_updated: 2026-09-17T08:31:24Z
day: '21'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.33232/001c.165333
external_id:
arxiv:
- '2512.14486'
fulldoi: https://doi.org/10.33232/001c.165333
has_accepted_license: '1'
intvolume: ' 9'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.2512.14486
month: '07'
oa: 1
oa_version: Published Version
publication: The Open Journal of Astrophysics
publication_identifier:
eissn:
- 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: yes
title: 'A first systematic study of [OIII] 88μm at z>8: two luminous oxygen lines
and a powerful ionized outflow in the first 600 million years'
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: 9
year: '2026'
...
---
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '20192'
abstract:
- lang: eng
text: We study the physical origin and spectroscopic impact of extreme nebular emission
in high-redshift galaxies. The nebular continuum, which can appear during an extreme
starburst, is of particular importance as it tends to redden UV slopes and has
a significant contribution to the UV luminosities of galaxies. Furthermore, its
shape can be used to infer the gas density and temperature of the interstellar
medium. First, we provide a theoretical background, showing how different stellar
populations (SPS models, initial mass functions (IMFs), and stellar temperatures)
and nebular conditions impact observed galaxy spectra. We demonstrate that, for
systems with strong nebular continuum emission, 1) UV fluxes can increase by up
to 0.7~mag (or more in the case of hot/massive stars) above the stellar continuum,
which may help reconcile the surprising abundance of bright high-redshift galaxies
and the elevated UV luminosity density at z>10, 2) at high gas densities, UV slopes
can redden from \beta<-2.5 to \beta\sim-1, 3) observational measurements of \xi_{\rm
ion} are gross underestimates, and 4) UV downturns from two-photon emission can
masquerade as damped Ly\alpha systems. Second, we present a dataset of 58 galaxies
observed with NIRSpec on JWST at 2.510 galaxies, finding
that UV slopes and UV downturns are in some cases redder or steeper than expected
from SPS models, which may hint at more exotic (e.g. hotter/more massive stars
or AGN) ionizing sources.
acknowledgement: 'HK thanks Andrey Kravtsov for insightful comments and thoughtful
discussions. We sincerely thank the PIs and Co-Is of the JWST programs where spectral
data was made publicly available on the DJA. We refer interested readers to the
following papers for survey descriptions regarding the spectral data: Bunker et
al. (2023a); D’Eugenio et al. (2024); Bezanson et al. (2022); Barrufet et al. (2024);
de Graaff et al. (2024); Finkelstein et al. (2024); Glazebrook et al. (2024); Pierel
et al. (2024); Siebert et al. (2024); Maseda et al. (2024). 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. These observations
are associated with programs listed in Table 1. AJC and AS acknowledge funding from
the “FirstGalaxies” Advanced Grant from the European Research Council (ERC) under
the European Union’s Horizon 2020 research and innovation programme (Grant agreement
No. 789056). '
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Harley
full_name: Katz, Harley
last_name: Katz
- first_name: Alex J.
full_name: Cameron, Alex J.
last_name: Cameron
- first_name: Aayush
full_name: Saxena, Aayush
last_name: Saxena
- first_name: Laia
full_name: Barrufet, Laia
last_name: Barrufet
- first_name: Nicholas
full_name: Choustikov, Nicholas
last_name: Choustikov
- 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: Richard S.
full_name: Ellis, Richard S.
last_name: Ellis
- first_name: Robert A.E.
full_name: Fosbury, Robert A.E.
last_name: Fosbury
- first_name: Kasper E.
full_name: Heintz, Kasper E.
last_name: Heintz
- first_name: Michael
full_name: Maseda, Michael
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: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
citation:
ama: 'Katz H, Cameron AJ, Saxena A, et al. 21 Balmer Jump Street: The nebular continuum
at high redshift and implications for the bright galaxy problem, UV continuum
slopes, and early stellar populations. The Open Journal of Astrophysics.
2025;8. doi:10.33232/001c.142570'
apa: 'Katz, H., Cameron, A. J., Saxena, A., Barrufet, L., Choustikov, N., Cleri,
N. J., … Oesch, P. A. (2025). 21 Balmer Jump Street: The nebular continuum at
high redshift and implications for the bright galaxy problem, UV continuum slopes,
and early stellar populations. The Open Journal of Astrophysics. Maynooth
Academic Publishing. https://doi.org/10.33232/001c.142570'
chicago: 'Katz, Harley, Alex J. Cameron, Aayush Saxena, Laia Barrufet, Nicholas
Choustikov, Nikko J. Cleri, Anna De Graaff, et al. “21 Balmer Jump Street: The
Nebular Continuum at High Redshift and Implications for the Bright Galaxy Problem,
UV Continuum Slopes, and Early Stellar Populations.” The Open Journal of Astrophysics.
Maynooth Academic Publishing, 2025. https://doi.org/10.33232/001c.142570.'
ieee: 'H. Katz et al., “21 Balmer Jump Street: The nebular continuum at high
redshift and implications for the bright galaxy problem, UV continuum slopes,
and early stellar populations,” The Open Journal of Astrophysics, vol.
8. Maynooth Academic Publishing, 2025.'
ista: 'Katz H, Cameron AJ, Saxena A, Barrufet L, Choustikov N, Cleri NJ, De Graaff
A, Ellis RS, Fosbury RAE, Heintz KE, Maseda M, Matthee JJ, Mcconachie I, Oesch
PA. 2025. 21 Balmer Jump Street: The nebular continuum at high redshift and implications
for the bright galaxy problem, UV continuum slopes, and early stellar populations.
The Open Journal of Astrophysics. 8.'
mla: 'Katz, Harley, et al. “21 Balmer Jump Street: The Nebular Continuum at High
Redshift and Implications for the Bright Galaxy Problem, UV Continuum Slopes,
and Early Stellar Populations.” The Open Journal of Astrophysics, vol.
8, Maynooth Academic Publishing, 2025, doi:10.33232/001c.142570.'
short: H. Katz, A.J. Cameron, A. Saxena, L. Barrufet, N. Choustikov, N.J. Cleri,
A. De Graaff, R.S. Ellis, R.A.E. Fosbury, K.E. Heintz, M. Maseda, J.J. Matthee,
I. Mcconachie, P.A. Oesch, The Open Journal of Astrophysics 8 (2025).
date_created: 2025-08-17T22:01:37Z
date_published: 2025-07-25T00:00:00Z
date_updated: 2025-09-30T14:29:33Z
day: '25'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.33232/001c.142570
external_id:
arxiv:
- '2408.03189'
file:
- access_level: open_access
checksum: ba469d132907147f9e86d87f9124dd14
content_type: application/pdf
creator: dernst
date_created: 2025-09-30T14:28:25Z
date_updated: 2025-09-30T14:28:25Z
file_id: '20412'
file_name: 2025_OpenJourAstrophysics_Katz.pdf
file_size: 1836432
relation: main_file
success: 1
file_date_updated: 2025-09-30T14:28:25Z
fulldoi: https://doi.org/10.33232/001c.142570
has_accepted_license: '1'
intvolume: ' 8'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
publication: The Open Journal of Astrophysics
publication_identifier:
eissn:
- 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: '21 Balmer Jump Street: The nebular continuum at high redshift and implications
for the bright galaxy problem, UV continuum slopes, and early stellar populations'
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: 8
year: '2025'
...