The evolution of the mass-size relation for early type galaxies from z 1 to the present: dependence on environment, mass-range and detailed morphology

We study the dependence of the galaxy size evolution on morphology, stellar mass and large scale environment for a sample of 298 group and 384 field quiescent earlytype galaxies from the COSMOS survey, selected from z � 1 to the present, and with masses log(M/M⊙) > 10.5. From a detailed morphological analysis we infer that � 80% of passive galaxies with mass log(M/M⊙) > 10.5 have an early-type morphology and that this fraction does not evolve over the last 6 Gyr. However the relative abundance of lenticular and elliptical galaxies depends on stellar mass. Elliptical galaxies dominate only at the very high mass end – log(M/M⊙) > 11 – while S0 galaxies dominate at lower stellar masses – 10.5 < log(M/M⊙) < 11.