High-redshift Galaxy Candidates at z = 9-10 as Revealed by JWST Observations of WHL0137-08

Abstract

We report the discovery of four galaxy candidates observed 450–600 Myr after the Big Bang with photometric redshifts between z ∼ 8.3 and 10.2 measured using James Webb Space Telescope (JWST) NIRCam imaging of the galaxy cluster WHL0137−08 observed in eight filters spanning 0.8–5.0 μm, plus nine Hubble Space Telescope filters spanning 0.4–1.7 μm. One candidate is gravitationally lensed with a magnification of μ ∼ 8, while the other three are located in a nearby NIRCam module with expected magnifications of μ  1.1. Using SED fitting, we estimate the stellar masses of these galaxies are typically in the range log M M  = 8.3–8.7. All appear young, with mass-weighted ages < 0.15 mag, and specific star formation rates sSFR ∼0.25–10 Gyr−1 for most. One z ∼ 9 candidate is consistent with an age