The Morphology-Density Relation of Galaxies at z~1.6

The relationship between galaxy morphology and environment has been well-studied in the local universe and at low redshift, showing that galaxies in dense clusters tend to be elliptical and bulge-like while galaxies in low-density fields tend to be spiral and disk-like. However, this relationship is less understood at higher redshifts, and the few studies at high-z rely on samples with incomplete redshift measurements and poorly constrained stellar masses. We explore the morphology-density relation at z~1.6, the tail end of cosmic noon, using a sample of 3 SpARCS clusters and 2 fields from 3D-HST/CANDELS. Using Sersic index as a proxy for galaxy morphology, we find that the morphology-density relation is already in place in clusters at this epoch. Additionally, we find a significant difference in the relationship between galaxy morphology and stellar mass in clusters compared to field environments. This suggests that the morphology-density relation may be driven by mass-dependent environmental processes.