The first GLIMPSE of the faint galaxy population at Cosmic Dawn with JWST : The evolution of the ultraviolet luminosity function across z ∼ 9−15

ABSTRACT Using ultra-deep James Webb Space Telescope (JWST)/NIRCam imaging from the GLIMPSE survey, enhanced by gravitational lensing from the Abell S1063 cluster, we investigate the faintest galaxies ever observed at redshifts $z\sim 9{\text{-}}15$. We identify 105 galaxy candidates spanning absolute ultraviolet (UV) magnitudes $M_{\mathrm{UV}}$$\sim -18$ to $-13$, about 3 mag fainter, on average, than prior JWST studies. We place strong constraints on the ultra-faint end of the UV luminosity function (UVLF), finding minimal evolution in the faint-end slope, from $\alpha =-2.01\pm 0.20$ at $z=9$ to $\alpha =-2.10\pm 0.19$ at $z=13$, in contrast to the rapid evolution observed at $z\sim 0{\text{-}}9$.…

• NS
  National Science Foundation

  Award: 864/23
• NA
  National Aeronautics and Space Administration

  Award: NAS 5-26555
• BF
  Bonfils-Stanton Foundation

  Award: 2109066
• ES
  Entomological Society of America
• BG
  Bishop Grosseteste University

  Award: 2020750
• AN
  Agence Nationale de la Recherche

  Award: ANR-21-CE31-0838
• SN
  Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung

  Award: 200020_207349
• MA
  Mitutoyo Association for Science and Technology