SIZES AND SURFACE BRIGHTNESS PROFILES OF QUIESCENT GALAXIES AT z ∼ 2

We use deep Hubble Space Telescope Wide Field Camera 3 near-infrared imaging obtained of the GOODS-South field as part of the CANDELS survey to investigate a stellar mass-limited sample of quiescent galaxies at 1.5 < z < 2.5. We measure surface brightness profiles for these galaxies using a method that properly measures low surface brightness flux at large radii. We find that quiescent galaxies at z similar to 2 very closely follow Sersic profiles, with n(median) = 3.7, and have no excess flux at large radii. Their effective radii are a factor of similar to 4 smaller than those of low-redshift quiescent galaxies of similar mass. However, there is a significant spread in sizes (delta(log10 re) = 0.24), with the largest z similar to 2 galaxies lying close to the z = 0 mass-size relation. We compare the stellar mass surface density profiles with those of massive elliptical galaxies in the Virgo Cluster and confirm that most of the mass growth which occurs between z similar to 2 and z = 0 must be due to accretion of material onto the outer regions of the galaxies. Additionally, we investigate the evolution in the size distribution of massive quiescent galaxies. We find that the minimum size growth required for z similar to 2 quiescent galaxies to fall within the z = 0 size distribution is a factor of similar to 2 smaller than the total median size growth between z similar to 2 and z = 0.