JWST properties of high-z HST-dark galaxies

However, due to the very limited photometry for individual galaxies, the true nature of these so-called HST-dark galaxies has remained elusive. Here, we present the first sample of such galaxies observed with very deep, high-resolution NIRCam imaging from the Early Release Science programme CEERS. 30 HST-dark sources are selected based on their red colours across 1.6-4.4 {mu}m.

Their physical properties are derived from 12-band multiwavelength photometry, including ancillary HST imaging. We find that these galaxies are generally heavily dust-obscured (A_V_ ~2 mag), massive (logM/M_{sun}_) ~10), star-forming sources at z ~ 2-8 with an observed surface density of ~0.8 arcmin^-2^. This suggests that an important fraction of massive galaxies may have been missing from our cosmic census at z > 3 all the way into the Epoch of Reionization.