Stellar mass-size relation for low M* galaxies

Galaxies are simultaneously modelled in multiple bands using the tools developed by the MegaMorph project, allowing robust size (i.e., half-light radius) estimates even for small, faint, and high redshift galaxies. We show that above 10^7^M_{sun}_, star-forming galaxies are well represented by a single power law on the mass-size plane over our entire redshift range.

Conversely, the stellar mass - size relation is steep for quiescent galaxies with stellar masses >=10^10.3^M_{sun}_ and flattens at lower masses, regardless of whether quiescence is selected based on star-formation activity, rest-frame colours, or structural characteristics. This flattening occurs at sizes of ~1kpc at z<=1. As a result, a double power law is preferred for the stellar mass-size relation of quiescent galaxies, at least above 10^7^M_{sun}_.