Date: 7/29/2024
Arxiv: JWST UNCOVER: The Overabundance of Ultraviolet-luminous Galaxies at
z>9
Published: 12/8/2023 3:18:47 PM
Updated: 7/26/2024 4:12:36 PM
Paper abstract: Over the past year, JWST has uncovered galaxies at record-breaking distancesup to z ~ 13. The JWST UNCOVER (ultra-deep NIRSpec and NIRcam observationsbefore the epoch of reionization) program has obtained ultra-deepmultiwavelength NIRCam imaging of the massive galaxy cluster Abell 2744 over~ 45 arcmin^{2} down to ~ 29.5 AB mag. Here, we present a robustultraviolet (UV) luminosity function derived through lensing clusters at99 in recent JWST studies. In particular, a double power-law (DPL) describesbetter the bright-end of the luminosity function compared to the classicalSchechter form. The number density of these bright galaxies is 10-100 timeslarger than theoretical predictions and previous findings based on Hubble SpaceTelescope (HST) observations. Additionally, we measure a star formation ratedensity of \rho_{\rm SFR} = 10^{-2.64} M_{\odot}~yr^{-1}~Mpc^{-3} atthese redshifts, which is 4 to 10 times higher than galaxy formation modelsthat assume a constant star formation efficiency. Future wide-area surveys andaccurate modeling of lensing-assisted observations will reliably constrain boththe bright and the dim end of the UV luminosity function at z>9, which willprovide key benchmarks for galaxy formation models.
