CEERS Spectroscopic Confirmation of NIRCam-selected z ≳ 8 Galaxy Candidates with JWST/NIRSpec: Initial Characterization of Their Properties
Author
Fujimoto, S.
Haro, P.A.
Dickinson, M.
Finkelstein, S.L.
Kartaltepe, J.S.
Larson, R.L.
Burgarella, D.
Bagley, M.B.
Behroozi, P.
Chworowsky, K.
Hirschmann, M.
Trump, J.R.
Wilkins, S.M.
Yung, L.Y.A.
Koekemoer, A.M.
Papovich, C.
Pirzkal, N.
Ferguson, H.C.
Fontana, A.
Grogin, N.A.
Grazian, A.

Kewley, L.J.
Kocevski, D.D.
Lotz, J.M.
Pentericci, L.
Ravindranath, S.
Somerville, R.S.
Amorín, R.O.
Backhaus, B.E.
Calabrò, A.
Casey, C.M.
Cooper, M.C.
Fernández, V.
Franco, M.
Giavalisco, M.
Hathi, N.P.
Harish, S.
Hutchison, T.A.
Iyer, K.G.
Jung, I.
Lucas, R.A.
Zavala, J.A.
Affiliation
Department of Astronomy and Steward Observatory, University of ArizonaIssue Date
2023-06-05
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American Astronomical SocietyCitation
Seiji Fujimoto et al 2023 ApJL 949 L25Journal
Astrophysical Journal LettersRights
© 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present JWST NIRSpec spectroscopy for 11 galaxy candidates with photometric redshifts of z ≃ 9 − 13 and M UV ∈ [ −21, −18] newly identified in NIRCam images in the Cosmic Evolution Early Release Science Survey. We confirm emission line redshifts for 7 galaxies at z = 7.762-8.998 using spectra at ∼1-5 μm either with the NIRSpec prism or its three medium-resolution (R ∼ 1000) gratings. For z ≃ 9 photometric candidates, we achieve a high confirmation rate of ≃90%, which validates the classical dropout selection from NIRCam photometry. No robust emission lines are identified in three galaxy candidates at z > 10, where the strong [O iii] and Hβ lines would be redshifted beyond the wavelength range observed by NIRSpec, and the Lyα continuum break is not detected with the sensitivity of the current data. Compared with Hubble Space Telescope-selected bright galaxies (M UV ≃ −22) that are similarly spectroscopically confirmed at z ≃ 8 − 9, these NIRCam-selected galaxies are characterized by lower star formation rates (SFRs; SFR ≃ 4 M ⊙ yr−1) and lower stellar masses (≃108 M ⊙), but with higher specific SFR (≃40 Gyr−1), higher [O iii]+Hβ equivalent widths (≃1100 Å), and elevated production efficiency of ionizing photons ( log ( ξ ion / Hz erg − 1 ) ≃ 25.8 ) induced by young stellar populations (<10 Myr) accounting for ≃20% of the galaxy mass, highlighting the key contribution of faint galaxies to cosmic reionization. Taking advantage of the homogeneous selection and sensitivity, we also investigate metallicity and ISM conditions with empirical calibrations using the [O iii]5008/Hβ ratio. We find that galaxies at z ≃ 8 − 9 have higher SFRs and lower metallicities than galaxies at similar stellar masses at z ≃ 2 − 6, which is generally consistent with the current galaxy formation and evolution models. © 2023. The Author(s). Published by the American Astronomical Society.Note
Open access journalISSN
2041-8205Version
Final Published Versionae974a485f413a2113503eed53cd6c53
10.3847/2041-8213/acd2d9
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Except where otherwise noted, this item's license is described as © 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.