Kazuharu HIMOTO
(Ehime University)
In order to classify morphology of galaxies in various stages of the galaxy merger/interaction, we use a new quantitative index which compares the surface brightness at the barycenter of the light distribution of a galaxy with the mean surface brightness of fluxes of the brightest 20% of light in the galaxy, as well as the well-known indices, M20 and A. We apply our new classification to the HST/ACS data for galaxies with M_V<-20 at 0.7<z<0.9 in the COSMOS field, and investigate relationship between the star formation activity and morphology of these merging/interacting galaxies.