We study the environmental dependence of color , stellar mass , and morphology by comparing galaxies in a forming cluster to those in the field at z = 1.6 with Hubble Space Telescope near-infrared imaging in the CANDELS/UDS field .
We quantify the morphology of the galaxies using the effective radius , r _ { \mathrm { eff } } , and Sérsic index , n .
In both the cluster and field , approximately half of the bulge-dominated galaxies ( n > 2 ) reside on the red sequence of the color-magnitude diagram , and most disk-dominated galaxies ( n < 2 ) have colors expected for star-forming galaxies .
There is weak evidence that cluster galaxies have redder rest-frame U - B colors and higher stellar masses compared to the field .
Star-forming galaxies in both the cluster and field show no significant differences in their morphologies .
In contrast , there is evidence that quiescent galaxies in the cluster have larger median effective radii and smaller Sérsic indices compared to the field with a significance of 2 \sigma .
These differences are most pronounced for galaxies at clustercentric distances 1 Mpc < \hbox { $R _ { \mathrm { proj } } $ } < 1.5 Mpc , which have low Sérsic indices and possibly larger effective radii , more consistent with star-forming galaxies at this epoch and in contrast to other quiescent galaxies .
We argue that star-forming galaxies are processed under the influence of the cluster environment at distances greater than the cluster-halo virial radius .
Our results are consistent with models where gas accretion onto these galaxies is suppressed from processes associated with the cluster environment .