2025/12/02 by Martorano, Marco, van der Wel, Arjen, Gebek, Andrea +7
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2512.02440
We present the redshift evolution of radial color gradients (in rest-frame U - V and V - J) for galaxies in the range 0.5< z <2.5 and investigate their origin and dependence on stellar mass. We select ∼ 10,200 galaxies with stellar masses M_⋆>109.5~M_\odot from publicly available JWST/NIRCam-selected catalogs. Using 2D Sérsic profile fits to account for PSF broadening, we perform spatially resolved SED fitting on HST and JWST/NIRCam photometry retrieving accurate rest-frame U - V and V - J color gradients within 2Re, F444W. Star-forming galaxies generally exhibit negative V - J color gradients that are strongly mass and redshift dependent. For massive star-forming galaxies (M_⋆>1010.5~M_\odot) at z>1.5 V - J colors are ≈ 0.5 mag redder within the effective radius than outside, on average. We find that, at all redshifts and across the entire stellar mass range, V - J gradients strongly correlate with global attenuation (AV), suggesting that they predominantly trace dust attenuation gradients. Edge-on galaxies are redder and have stronger gradients at all z, although the correlation weakens at higher z. The U - V and V - J color gradients in the quiescent galaxy population, in contrast, are weakly negative (from ≈ -0.1 to ≈- 0.2 mag), though significant, and show little or no dependence on stellar mass, redshift or axis ratio. The implication is that quiescent galaxies must be largely transparent, with low AV, and color gradients mostly attributable to stellar population gradients.