CEERS Spectroscopic Confirmation of NIRCam-selected z ≳ 8 Galaxy Candidates with JWST/NIRSpec: Initial Characterization of Their Properties

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Fujimoto_2023_ApJL_949_L25.pdf (3.62 MB)

Date

2023/06/01

Authors

Fujimoto, Seiji, Haro, Pablo Arrabal, Dickinson, Mark, Finkelstein, Steven L., Kartaltepe, Jeyhan S., Larson, Rebecca L., Burgarella, Denis, Bagley, Micaela B., Behroozi, Peter, Chworowsky, Katherine, Hirschmann, Michaela, Trump, Jonathan R., Wilkins, Stephen M., Yung, L. Y. Aaron, Koekemoer, Anton M., Papovich, Casey, Pirzkal, Nor, Ferguson, Henry C., Fontana, Adriano, Grogin, Norman A., Grazian, Andrea, Kewley, Lisa J., Kocevski, Dale D., Lotz, Jennifer M., Pentericci, Laura, Ravindranath, Swara, Somerville, Rachel S., Wilkins, Stephen M., Amorin, Ricardo O., Backhaus, Bren E., Calabro, Antonello, Casey, Caitlin M., Cooper, M. C., Fernandez, Vital, Franco, Maximilien, Giavalisco, Mauro, Hathi, Nimish P., Harish, Santosh, Hutchison, Taylor A., Iyer, Kartheik G., Jung, Intae, Lucas, Ray A., Zavala, Jorge A.

Journal Title

Journal ISSN

Volume Title

Publisher

IOP Publishing Ltd

Abstract

We present JWST NIRSpec spectroscopy for 11 galaxy candidates with photometric redshifts of z similar or equal to 9 - 13 and M-UV is an element of [ -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 similar to 1-5 mu m either with the NIRSpec prism or its three medium-resolution (R similar to 1000) gratings. For z similar or equal to 9 photometric candidates, we achieve a high confirmation rate of similar or equal to 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 beta lines would be redshifted beyond the wavelength range observed by NIRSpec, and the Ly alpha continuum break is not detected with the sensitivity of the current data. Compared with Hubble Space Telescope-selected bright galaxies (M-UV similar or equal to -22) that are similarly spectroscopically confirmed at z similar or equal to 8 - 9, these NIRCam-selected galaxies are characterized by lower star formation rates (SFRs, SFR similar or equal to 4 M-circle dot yr(-1)) and lower stellar masses (similar or equal to 10(8)M(circle dot)), but with higher specific SFR (similar or equal to 40 Gyr(-1)), higher [O iii]+H beta equivalent widths (similar or equal to 1100 angstrom), and elevated production efficiency of ionizing photons (log(xi(ion)/Hz erg(-1)) similar or equal to 25.8) induced by young stellar populations (<10 Myr) accounting for similar or equal to 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 beta ratio. We find that galaxies at z similar or equal to 8 - 9 have higher SFRs and lower metallicities than galaxies at similar stellar masses at z similar or equal to 2 - 6, which is generally consistent with the current galaxy formation and evolution models.

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Keywords

UV LUMINOSITY FUNCTIONS, PHOTON PRODUCTION EFFICIENCY, HIGH-REDSHIFT GALAXIES, STAR-FORMING GALAXIES, MASS-METALLICITY RELATION, EPOCH SIMULATIONS FLARES, HIGH-EQUIVALENT-WIDTH, LY-ALPHA EMITTERS, STELLAR MASS, MOSDEF SURVEY

Citation

URI

https://publicacionesabiertas.userena.cl/handle/123456789/131

Collections

Astronomía