2025ApJ...991..222O

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 ${r}_{{{\rm{e}}}}=13{3}_{-12}^{+13}$ pc and a standard deviation of ${\sigma }_{{\mathrm{ln}}\,{r}_{{{\rm{e}}}}}=0.52\pm 0.08$. 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 ${r}_{{{\rm{e}}}}/{r}_{{\mathrm{vir}}}=0.01{5}_{-0.005}^{+0.015}$, 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 ${r}_{{{\rm{e}}}}=5{5}_{-6}^{+5}$ 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.