Abstract We homogeneously investigate the morphological properties of 169 galaxies at z ∼ 10–16 with deep JWST NIRCam images employing our established techniques of GALFIT modeling and uncertainty evaluation (systematics+statistics). We obtain effective radii r e ranging 20–500 pc, with a distribution significantly broader than the scatter made by the uncertainties. We find that the r e distribution is well described by a log-normal distribution with a mean of r e = 13 3 − 12 + 13 pc and a standard deviation of σ ln r e = 0.52 ± 0.08 . The standard deviation is comparable to that of local galaxies, indicating no significant evolution over z ∼ 0–10. We also find that the axis ratio distribution is nearly uniform, statistically similar to that of local spirals. We estimate the virial radius r vir from the stellar masses via the star formation main sequence and stellar-to-halo mass relation, obtaining a stellar-to-halo size ratio r e / r vir = 0.01 5 − 0.005 + 0.015 , which is comparable to those of star-forming galaxies in the local and low- z Universe. Our results of (1) the log-normal r e distribution, (2) the uniform axis ratio distribution, and (3) a mean radial profile consistent with an exponential profile ( n = 1.3 ± 0.6) suggest that galaxies at z ∼ 10–16 generally follow the classical galaxy disk formation scenario with a specific disk angular momentum fraction of j d / m d ∼ 0.5–1. Interestingly, we identify two remarkable outliers GN-z11 ( z spec = 10.60) and GHZ2 ( z spec = 12.34) with r e = 5 5 − 6 + 5 pc and 39 ± 11 pc, respectively, that may not be explained by disk structures but by active galactic nucleus or compact star-forming galaxies merging underway in short periods of time, as reproduced in numerical simulations.
Ono et al. (Tue,) studied this question.