The Astrophysical Journal Letters (Jan 2023)
CEERS Spectroscopic Confirmation of NIRCam-selected z ≳ 8 Galaxy Candidates with JWST/NIRSpec: Initial Characterization of Their Properties
- Seiji Fujimoto,
- Pablo Arrabal Haro,
- Mark Dickinson,
- Steven L. Finkelstein,
- Jeyhan S. Kartaltepe,
- Rebecca L. Larson,
- Denis Burgarella,
- Micaela B. Bagley,
- Peter Behroozi,
- Katherine Chworowsky,
- Michaela Hirschmann,
- Jonathan R. Trump,
- Stephen M. Wilkins,
- L. Y. Aaron Yung,
- Anton M. Koekemoer,
- Casey Papovich,
- Nor Pirzkal,
- Henry C. Ferguson,
- Adriano Fontana,
- Norman A. Grogin,
- Andrea Grazian,
- Lisa J. Kewley,
- Dale D. Kocevski,
- Jennifer M. Lotz,
- Laura Pentericci,
- Swara Ravindranath,
- Rachel S. Somerville,
- Stephen M. Wilkins,
- Ricardo O. Amorín,
- Bren E. Backhaus,
- Antonello Calabrò,
- Caitlin M. Casey,
- M. C. Cooper,
- Vital Fernández,
- Maximilien Franco,
- Mauro Giavalisco,
- Nimish P. Hathi,
- Santosh Harish,
- Taylor A. Hutchison,
- Kartheik G. Iyer,
- Intae Jung,
- Ray A. Lucas,
- Jorge A. Zavala
Affiliations
- Seiji Fujimoto
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- Pablo Arrabal Haro
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory, 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Mark Dickinson
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory, 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Steven L. Finkelstein
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- Jeyhan S. Kartaltepe
- ORCiD
- Laboratory for Multiwavelength Astrophysics, School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623, USA
- Rebecca L. Larson
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- Denis Burgarella
- ORCiD
- Aix Marseille Univ, CNRS, CNES, LAM Marseille, France
- Micaela B. Bagley
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- Peter Behroozi
- ORCiD
- Department of Astronomy and Steward Observatory, University of Arizona , Tucson, AZ 85721, USA; Division of Science, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Katherine Chworowsky
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- Michaela Hirschmann
- ORCiD
- Institute for Physics, Laboratory for Galaxy Evolution and Spectral modelling, Ecole Polytechnique Federale de Lausanne, Observatoire de Sauverny, Chemin Pegasi 51, 1290 Versoix, Switzerland; INAF, Osservatorio Astronomico di Trieste, Via Tiepolo 11, I-34131 Trieste, Italy
- Jonathan R. Trump
- ORCiD
- Department of Physics, 196 Auditorium Road, Unit 3046, University of Connecticut , Storrs, CT 06269, USA
- Stephen M. Wilkins
- ORCiD
- Astronomy Centre, University of Sussex , Falmer, Brighton BN1 9QH, UK; Institute of Space Sciences and Astronomy, University of Malta , Msida MSD 2080, Malta
- L. Y. Aaron Yung
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771, USA
- Anton M. Koekemoer
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Casey Papovich
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX, 77843-4242 USA; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX, 77843-4242 USA
- Nor Pirzkal
- ORCiD
- ESA/AURA Space Telescope Science Institute , 3700, San Martin Drive, MD 21218, USA
- Henry C. Ferguson
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Adriano Fontana
- ORCiD
- INAF Osservatorio Astronomico di Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Rome, Italy
- Norman A. Grogin
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Andrea Grazian
- ORCiD
- INAF–Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122, Padova, Italy
- Lisa J. Kewley
- ORCiD
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
- Dale D. Kocevski
- ORCiD
- Department of Physics and Astronomy, Colby College, Waterville, ME 04901, USA
- Jennifer M. Lotz
- ORCiD
- Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory, 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Laura Pentericci
- ORCiD
- INAF Osservatorio Astronomico di Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Rome, Italy
- Swara Ravindranath
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Rachel S. Somerville
- ORCiD
- Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA
- Stephen M. Wilkins
- ORCiD
- Astronomy Centre, University of Sussex , Falmer, Brighton BN1 9QH, UK; Institute of Space Sciences and Astronomy, University of Malta , Msida MSD 2080, Malta
- Ricardo O. Amorín
- ORCiD
- Instituto de Investigación Multidisciplinar en Ciencia y Tecnología, Universidad de La Serena, Raul Bitrán 1305, La Serena 2204000, Chile; Departamento de Astronomía, Universidad de La Serena , Av. Juan Cisternas 1200 Norte, La Serena 1720236, Chile
- Bren E. Backhaus
- ORCiD
- Department of Physics, 196 Auditorium Road, Unit 3046, University of Connecticut , Storrs, CT 06269, USA
- Antonello Calabrò
- ORCiD
- INAF Osservatorio Astronomico di Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Rome, Italy
- Caitlin M. Casey
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- M. C. Cooper
- ORCiD
- Department of Physics & Astronomy, University of California , Irvine, 4129 Reines Hall, Irvine, CA 92697, USA
- Vital Fernández
- ORCiD
- Departamento de Astronomía, Universidad de La Serena , Av. Juan Cisternas 1200 Norte, La Serena 1720236, Chile
- Maximilien Franco
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA ; [email protected]
- Mauro Giavalisco
- ORCiD
- University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, MA 01003-9305, USA
- Nimish P. Hathi
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Santosh Harish
- ORCiD
- Laboratory for Multiwavelength Astrophysics, School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623, USA
- Taylor A. Hutchison
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771, USA
- Kartheik G. Iyer
- ORCiD
- Dunlap Institute for Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4, Canada
- Intae Jung
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Ray A. Lucas
- ORCiD
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
- Jorge A. Zavala
- ORCiD
- Division of Science, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- DOI
- https://doi.org/10.3847/2041-8213/acd2d9
- Journal volume & issue
-
Vol. 949,
no. 2
p. L25
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 μ m 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 H β lines would be redshifted beyond the wavelength range observed by NIRSpec, and the Ly α 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 (≃10 ^8 M _⊙ ), but with higher specific SFR (≃40 Gyr ^−1 ), higher [O iii ]+H β equivalent widths (≃1100 Å), and elevated production efficiency of ionizing photons ( $\mathrm{log}({\xi }_{\mathrm{ion}}/\mathrm{Hz}\,{\mathrm{erg}}^{-1})\simeq 25.8$ ) 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 /H β 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.
Keywords
