---
DOAJ_listed: '1'
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '22817'
abstract:
- lang: eng
  text: Using deep, medium-resolution, JWST rest-optical spectra of a sample of typical
    star-forming galaxies (Lyman-break galaxies and Lyman-α emitters) from the LyC22
    survey at z ∼ 3, we determined the nebular abundances of N, O, and Ne relative
    to H for a subsample of 25 objects with a direct method based on auroral [O III]
    λ4363 line detections. Our measurements increased the number of accurate N/O determinations
    at z ∼ 2 − 4 using a homogeneous approach. We found a mean value of log(N/O) =
    −+0.25−0.21 over a metallicity range of 12 + log(O/H) = 7.56 to 8.44. The observed
    N/O ratio and scatter are indistinguishable from that observed in low-z galaxies
    and H II regions over the same metallicity range, thus showing no redshift evolution
    of N/O for typical galaxies over a significant fraction of cosmic time. We also
    show that typical z ∼ 3 galaxies have a similar offset in the BPT diagram to galaxies
    from the low-z Lyman Continuum Survey (LzLCS) when compared to the average of
    SDSS galaxies, and we demonstrate that this offset is not due to enhanced nitrogen
    abundances. Our results establish a basis for future studies of the evolution
    of N and O at higher redshifts.
acknowledgement: "Y.I., N.G., R.M.-C., and D.S. acknowledge support from\r\nproject
  No. 224866 carried out in the framework of the Joint Call “UkrainianSwiss Joint
  Research Projects: Call for Proposals 2023”. This work is based in\r\npart on observations
  made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from
  the Mikulski Archive for Space Telescopes\r\nat the Space Telescope Science Institute,
  which is operated by the Association\r\nof Universities for Research in Astronomy,
  Inc., under NASA contract NAS 5-\r\n03127 for JWST. These observations are associated
  with program # 1869. Support for program # 1869 was provided by NASA through a grant
  from the Space\r\nTelescope Science Institute, which is operated by the Association
  of Universities\r\nfor Research in Astronomy, Inc., under NASA contract NAS 5-03127"
article_number: A242
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: D.
  full_name: Schaerer, D.
  last_name: Schaerer
- first_name: Y. I.
  full_name: Izotov, Y. I.
  last_name: Izotov
- first_name: R.
  full_name: Marques-Chaves, R.
  last_name: Marques-Chaves
- first_name: C. C.
  full_name: Steidel, C. C.
  last_name: Steidel
- first_name: N.
  full_name: Reddy, N.
  last_name: Reddy
- first_name: A. E.
  full_name: Shapley, A. E.
  last_name: Shapley
- first_name: Sara
  full_name: Mascia, Sara
  id: edaf889c-c7cd-11ef-ab1b-bb28c431bd29
  last_name: Mascia
- first_name: J.
  full_name: Chisholm, J.
  last_name: Chisholm
- first_name: S. R.
  full_name: Flury, S. R.
  last_name: Flury
- first_name: N.
  full_name: Guseva, N.
  last_name: Guseva
- first_name: T.
  full_name: Heckman, T.
  last_name: Heckman
- first_name: A.
  full_name: Henry, A.
  last_name: Henry
- first_name: A. K.
  full_name: Inoue, A. K.
  last_name: Inoue
- first_name: I.
  full_name: Jung, I.
  last_name: Jung
- first_name: H.
  full_name: Kusakabe, H.
  last_name: Kusakabe
- first_name: K.
  full_name: Mawatari, K.
  last_name: Mawatari
- first_name: P.
  full_name: Oesch, P.
  last_name: Oesch
- first_name: G.
  full_name: Östlin, G.
  last_name: Östlin
- first_name: L.
  full_name: Pentericci, L.
  last_name: Pentericci
- first_name: N.
  full_name: Roy, N.
  last_name: Roy
- first_name: A.
  full_name: Saldana-Lopez, A.
  last_name: Saldana-Lopez
- first_name: R.
  full_name: Sato, R.
  last_name: Sato
- first_name: E.
  full_name: Vanzella, E.
  last_name: Vanzella
- first_name: A.
  full_name: Verhamme, A.
  last_name: Verhamme
- first_name: B.
  full_name: Wang, B.
  last_name: Wang
citation:
  ama: Schaerer D, Izotov YI, Marques-Chaves R, et al. Nitrogen abundances in star-forming
    galaxies 2.2 Gyr after the Big Bang are not elevated. <i>Astronomy &#38; Astrophysics</i>.
    2026;708. doi:<a href="https://doi.org/10.1051/0004-6361/202556832">10.1051/0004-6361/202556832</a>
  apa: Schaerer, D., Izotov, Y. I., Marques-Chaves, R., Steidel, C. C., Reddy, N.,
    Shapley, A. E., … Wang, B. (2026). Nitrogen abundances in star-forming galaxies
    2.2 Gyr after the Big Bang are not elevated. <i>Astronomy &#38; Astrophysics</i>.
    EDP Sciences. <a href="https://doi.org/10.1051/0004-6361/202556832">https://doi.org/10.1051/0004-6361/202556832</a>
  chicago: Schaerer, D., Y. I. Izotov, R. Marques-Chaves, C. C. Steidel, N. Reddy,
    A. E. Shapley, Sara Mascia, et al. “Nitrogen Abundances in Star-Forming Galaxies
    2.2 Gyr after the Big Bang Are Not Elevated.” <i>Astronomy &#38; Astrophysics</i>.
    EDP Sciences, 2026. <a href="https://doi.org/10.1051/0004-6361/202556832">https://doi.org/10.1051/0004-6361/202556832</a>.
  ieee: D. Schaerer <i>et al.</i>, “Nitrogen abundances in star-forming galaxies 2.2
    Gyr after the Big Bang are not elevated,” <i>Astronomy &#38; Astrophysics</i>,
    vol. 708. EDP Sciences, 2026.
  ista: Schaerer D, Izotov YI, Marques-Chaves R, Steidel CC, Reddy N, Shapley AE,
    Mascia S, Chisholm J, Flury SR, Guseva N, Heckman T, Henry A, Inoue AK, Jung I,
    Kusakabe H, Mawatari K, Oesch P, Östlin G, Pentericci L, Roy N, Saldana-Lopez
    A, Sato R, Vanzella E, Verhamme A, Wang B. 2026. Nitrogen abundances in star-forming
    galaxies 2.2 Gyr after the Big Bang are not elevated. Astronomy &#38; Astrophysics.
    708, A242.
  mla: Schaerer, D., et al. “Nitrogen Abundances in Star-Forming Galaxies 2.2 Gyr
    after the Big Bang Are Not Elevated.” <i>Astronomy &#38; Astrophysics</i>, vol.
    708, A242, EDP Sciences, 2026, doi:<a href="https://doi.org/10.1051/0004-6361/202556832">10.1051/0004-6361/202556832</a>.
  short: D. Schaerer, Y.I. Izotov, R. Marques-Chaves, C.C. Steidel, N. Reddy, A.E.
    Shapley, S. Mascia, J. Chisholm, S.R. Flury, N. Guseva, T. Heckman, A. Henry,
    A.K. Inoue, I. Jung, H. Kusakabe, K. Mawatari, P. Oesch, G. Östlin, L. Pentericci,
    N. Roy, A. Saldana-Lopez, R. Sato, E. Vanzella, A. Verhamme, B. Wang, Astronomy
    &#38; Astrophysics 708 (2026).
das_tickbox: '1'
dataavailabilitystatement: "The data used are publicly available at the Mikulski Archive
  for Space Telescope (MAST),\r\nand can be accessed at https://dx.doi.org/10.17909/x6d5-vd44."
date_created: 2026-09-06T22:01:57Z
date_published: 2026-04-01T00:00:00Z
date_updated: 2026-09-09T12:59:51Z
day: '01'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.1051/0004-6361/202556832
external_id:
  arxiv:
  - '2601.06968'
file:
- access_level: open_access
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  creator: dernst
  date_created: 2026-09-09T12:55:37Z
  date_updated: 2026-09-09T12:55:37Z
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file_date_updated: 2026-09-09T12:55:37Z
fulldoi: https://doi.org/10.1051/0004-6361/202556832
has_accepted_license: '1'
intvolume: '       708'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '04'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
  eissn:
  - 1432-0746
  issn:
  - 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
researchdata_availability: yes
scopus_import: '1'
status: public
supplementarymaterial: no
title: Nitrogen abundances in star-forming galaxies 2.2 Gyr after the Big Bang are
  not elevated
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: 708
year: '2026'
...