학술논문
CEERS Spectroscopic Confirmation of NIRCam-selected z ≳ 8 Galaxy Candidates with JWST/NIRSpec: Initial Characterization of Their Properties
Document Type
article
Author
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; 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
Source
The Astrophysical Journal Letters, Vol 949, Iss 2, p L25 (2023)
Subject
Language
English
ISSN
2041-8213
2041-8205
2041-8205
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 (