The Astrophysical Journal Letters (Jan 2023)

CEERS Key Paper. I. An Early Look into the First 500 Myr of Galaxy Formation with JWST

  • Steven L. Finkelstein,
  • Micaela B. Bagley,
  • Henry C. Ferguson,
  • Stephen M. Wilkins,
  • Jeyhan S. Kartaltepe,
  • Casey Papovich,
  • L. Y. Aaron Yung,
  • Pablo Arrabal Haro,
  • Peter Behroozi,
  • Mark Dickinson,
  • Dale D. Kocevski,
  • Anton M. Koekemoer,
  • Rebecca L. Larson,
  • Aurélien Le Bail,
  • Alexa M. Morales,
  • Pablo G. Pérez-González,
  • Denis Burgarella,
  • Romeel Davé,
  • Michaela Hirschmann,
  • Rachel S. Somerville,
  • Stijn Wuyts,
  • Volker Bromm,
  • Caitlin M. Casey,
  • Adriano Fontana,
  • Seiji Fujimoto,
  • Jonathan P. Gardner,
  • Mauro Giavalisco,
  • Andrea Grazian,
  • Norman A. Grogin,
  • Nimish P. Hathi,
  • Taylor A. Hutchison,
  • Saurabh W. Jha,
  • Shardha Jogee,
  • Lisa J. Kewley,
  • Allison Kirkpatrick,
  • Arianna S. Long,
  • Jennifer M. Lotz,
  • Laura Pentericci,
  • Justin D. R. Pierel,
  • Nor Pirzkal,
  • Swara Ravindranath,
  • Russell E. Ryan Jr.,
  • Jonathan R. Trump,
  • Guang Yang,
  • Rachana Bhatawdekar,
  • Laura Bisigello,
  • Véronique Buat,
  • Antonello Calabrò,
  • Marco Castellano,
  • Nikko J. Cleri,
  • M. C. Cooper,
  • Darren Croton,
  • Emanuele Daddi,
  • Avishai Dekel,
  • David Elbaz,
  • Maximilien Franco,
  • Eric Gawiser,
  • Benne W. Holwerda,
  • Marc Huertas-Company,
  • Anne E. Jaskot,
  • Gene C. K. Leung,
  • Ray A. Lucas,
  • Bahram Mobasher,
  • Viraj Pandya,
  • Sandro Tacchella,
  • Benjamin J. Weiner,
  • Jorge A. Zavala

DOI
https://doi.org/10.3847/2041-8213/acade4
Journal volume & issue
Vol. 946, no. 1
p. L13

Abstract

Read online

We present an investigation into the first 500 Myr of galaxy evolution from the Cosmic Evolution Early Release Science (CEERS) survey. CEERS, one of 13 JWST ERS programs, targets galaxy formation from z ∼ 0.5 to >10 using several imaging and spectroscopic modes. We make use of the first epoch of CEERS NIRCam imaging, spanning 35.5 arcmin ^2 , to search for candidate galaxies at z > 9. Following a detailed data reduction process implementing several custom steps to produce high-quality reduced images, we perform multiband photometry across seven NIRCam broad- and medium-band (and six Hubble broadband) filters focusing on robust colors and accurate total fluxes. We measure photometric redshifts and devise a robust set of selection criteria to identify a sample of 26 galaxy candidates at z ∼ 9–16. These objects are compact with a median half-light radius of ∼0.5 kpc. We present an early estimate of the z ∼ 11 rest-frame ultraviolet (UV) luminosity function, finding that the number density of galaxies at M _UV ∼ −20 appears to evolve very little from z ∼ 9 to 11. We also find that the abundance (surface density [arcmin ^−2 ]) of our candidates exceeds nearly all theoretical predictions. We explore potential implications, including that at z > 10, star formation may be dominated by top-heavy initial mass functions, which would result in an increased ratio of UV light per unit halo mass, though a complete lack of dust attenuation and/or changing star formation physics may also play a role. While spectroscopic confirmation of these sources is urgently required, our results suggest that the deeper views to come with JWST should yield prolific samples of ultrahigh-redshift galaxies with which to further explore these conclusions.

Keywords