Two Remarkably Luminous Galaxy Candidates at z ≈ 10–12 Revealed by JWST

Abstract The first few 100 Myr at z > 10 mark the last major uncharted epoch in the history of the universe, where only a single galaxy (GN-z11 at z ≈ 11) is currently spectroscopically confirmed. Here we present a search for luminous z > 10 galaxies with JWST/NIRCam photometry spanning ≈1–5 μ m and covering 49 arcmin 2 from the public JWST Early Release Science programs (CEERS and GLASS). Our most secure candidates are two M UV ≈ −21 systems: GLASS-z12 and GLASS-z10. These galaxies display abrupt ≳1.8 mag breaks in their spectral energy distributions (SEDs), consistent with complete absorption of flux bluewards of Ly α that is redshifted to z = 12.4 − 0.3 + 0.1 and z = 10.4 − 0.5 + 0.4…

• NS
  National Science Foundation
• NA
  National Aeronautics and Space Administration

  Awards: NAS5-03127, NASA contract NAS5-26555, NAS5-26555, HST-HF2-51515.001-A
• ST
  Space Telescope Science Institute

  Awards: NAS5-03127, NAS5-26555, 26555, HST-HF2-51515.001-A
• NR
  National Research Foundation
• SN
  Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung

  Awards: 26555, 200020_207349
• DG
  Danmarks Grundforskningsfond

  Award: No. 140
• NO
  Nederlandse Organisatie voor Wetenschappelijk Onderzoek

  Award: TOP1.16.057