Abstract
We report detections of the [O iii]λ4364 auroral emission line for 16 galaxies at z = 2.1-8.7, measured from JWST/NIRSpec observations obtained as part of the Cosmic Evolution Early Release Science (CEERS) survey program. We combine this CEERS sample with 9 objects from the literature at z = 4−9 with auroral-line detections from JWST/NIRSpec and 21 galaxies at z = 1.4−3.7 with auroral-line detections from ground-based spectroscopy. We derive electron temperature (T e) and direct-method oxygen abundances for the combined sample of 46 star-forming galaxies at z = 1.4−8.7. We use these measurements to construct the first high-redshift empirical T e-based metallicity calibrations for the strong-line ratios [O iii]/Hβ, [O ii]/Hβ, R23 = ([O iii]+[O ii])/Hβ, [O iii]/[O ii], and [Ne iii]/[O ii]. These new calibrations are valid over 12+log(O/H) = 7.4−8.3 and can be applied to samples of star-forming galaxies at z = 2−9, leading to an improvement in the accuracy of metallicity determinations at Cosmic Noon and in the Epoch of Reionization. The high-redshift strong-line relations are offset from calibrations based on typical z ∼ 0 galaxies or H ii regions, reflecting the known evolution of ionization conditions between z ∼ 0 and z ∼ 2. Deep spectroscopic programs with JWST/NIRSpec promise to improve statistics at the low and high ends of the metallicity range covered by the current sample, as well as to improve the detection rate of [N ii]λ6585 and thus allow the future assessment of N-based indicators. These new high-redshift calibrations will enable accurate characterizations of metallicity scaling relations at high redshift, improving our understanding of feedback and baryon cycling in the early Universe.
| Original language | English |
|---|---|
| Article number | 24 |
| Journal | Astrophysical Journal |
| Volume | 962 |
| Issue number | 1 |
| DOIs | |
| State | Published - Feb 1 2024 |
Bibliographical note
Publisher Copyright:© 2024. The Author(s). Published by the American Astronomical Society.
Funding
We would like to thank the entire CEERS team for designing and executing the Early Release Science observations used in this work, most especially for designing the NIRSpec MSA observations. 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 NAS5-03127 for JWST. The specific observations analyzed can be accessed via DOI:10.17909/z7p0-8481. Support for this work was provided through the NASA Hubble Fellowship grant #HST-HF2-51469.001-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. We also acknowledge support from NASA grant JWST-GO-01914. The Cosmic Dawn Center is funded by the Danish National Research Foundation (DNRF) under grant #140. Cloud-based data processing, and file storage for this work is provided by the AWS Cloud Credits for Research program. We would like to thank the entire CEERS team for designing and executing the Early Release Science observations used in this work, most especially for designing the NIRSpec MSA observations. 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 NAS5-03127 for JWST. The specific observations analyzed can be accessed via DOI: 10.17909/z7p0-8481 . Support for this work was provided through the NASA Hubble Fellowship grant #HST-HF2-51469.001-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. We also acknowledge support from NASA grant JWST-GO-01914. The Cosmic Dawn Center is funded by the Danish National Research Foundation (DNRF) under grant #140. Cloud-based data processing, and file storage for this work is provided by the AWS Cloud Credits for Research program.
| Funders | Funder number |
|---|---|
| National Aeronautics and Space Administration | #HST-HF2-51469.001-A, NAS5-03127 |
| National Aeronautics and Space Administration | |
| Space Telescope Science Institute | NAS5-26555, JWST-GO-01914 |
| Space Telescope Science Institute | |
| Danmarks Grundforskningsfond | 140 |
| Danmarks Grundforskningsfond |
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science
Fingerprint
Dive into the research topics of 'Direct Te-based Metallicities of z = 2-9 Galaxies with JWST/NIRSpec: Empirical Metallicity Calibrations Applicable from Reionization to Cosmic Noon'. Together they form a unique fingerprint.Cite this
- APA
- Author
- BIBTEX
- Harvard
- Standard
- RIS
- Vancouver