Stellar Half-Mass Radii of $0.5<z<2.3$ Galaxies: Comparison with JWST/NIRCam Half-Light Radii

Arjen van der Wel, Marco Martorano, Boris Haussler, Kalina V. Nedkova, Tim B. Miller, Gabriel B. Brammer, Glenn van de Ven, Joel Leja, Rachel S. Bezanson, Adam Muzzin, Danilo Marchesini, Anna de Graaff, Mariska Kriek, Eric F. Bell, Marijn Franx

Published 2023-07-06Version 1

We use CEERS JWST/NIRCam imaging to measure rest-frame near-IR light profiles of $>$500 $M_\star>10^{10}~M_\odot$ galaxies in the redshift range $0.5<z<2.3$. We compare the resulting rest-frame 1.5-2$\mu$m half-light radii ($R_{\rm{NIR}}$) with stellar half-mass radii (\rmass) derived with multi-color light profiles from CANDELS HST imaging. In general agreement with previous work, we find that $R_{\rm{NIR}}$ and \rmass~are up to 40\%~smaller than the rest-frame optical half-light radius $R_{\rm{opt}}$. The agreement between $R_{\rm{NIR}}$ and \rmass~is excellent, with negligible systematic offset ($<$0.03 dex) up to $z=2$ for quiescent galaxies and up to $z=1.5$ for star-forming galaxies. We also deproject the profiles to estimate \rmassd, the radius of a sphere containing 50\% of the stellar mass. We present the $R-M_\star$ distribution of galaxies at $0.5<z<1.5$, comparing $R_{\rm{opt}}$, \rmass~and \rmassd. The slope is significantly flatter for \rmass~and \rmassd~ compared to $R_{\rm{opt}}$, mostly due to downward shifts in size for massive star-forming galaxies, while \rmass~and \rmassd~do not show markedly different trends. Finally, we show rapid size evolution ($R\propto (1+z)^{-1.7\pm0.1}$) for massive ($M_\star>10^{11}~M_\odot$) quiescent galaxies between $z=0.5$ and $z=2.3$, again comparing $R_{\rm{opt}}$, \rmass~and \rmassd. We conclude that the main tenets of the size evolution narrative established over the past 20 years, based on rest-frame optical light profile analysis, still hold in the era of JWST/NIRCam observations in the rest-frame near-IR.