Key points are not available for this paper at this time.
We present a comprehensive search and analysis of high-redshift galaxies in a suite of nine public JWST extragalactic fields taken in Cycle 1, covering a total effective search area of 358 arcmin². Through conservative (8σ) photometric selection, we identify 341 galaxies at 51. 5\, σ below the derived size-mass slope. These compact sources exhibit a high star formation surface density Σ ₒ₅ₑ>10\, M_\, yr^{-1\, kpc^-2}, a range in which only <0. 01\, \% of the local star-forming galaxy sample is found. For those with available NIRSpec data, no evidence of ongoing supermassive black hole accretion is observed. A potential explanation for the observed high OIII-to-Hbeta ratios could be high shock velocities, likely originating within intense star-forming regions characterized by high Σ ₒ₅ₑ. Lastly, we find that the rest-frame UV and optical sizes of our sample are comparable. Our results are consistent with these early galaxies building up their structures inside-out and yet to exhibit the strong color gradient seen at lower redshift.
Morishita et al. (Wed,) studied this question.