Yuki SATOH
(Ehime University)
We investigated the distribution of apparent axial ratio for galaxies at 0.2<z<1.0 in the COSMOS field, in order to reveal the relationship between galaxy shape and quenching of star formation. We divided photo-z selected galaxies with Mstar > 10^9 Msun into passive and star-forming populations and examined the evolution of the distribution of axial ratio for these populations separately using the HST/ACS data. We found that the fraction of flattened passive galaxies significantly increases with time from z~0.8 to z~0.4, while that of star-forming galaxies is nearly constant over the same redshift range.