The galaxy population of the core of the Coma cluster

Abstract

ABSTRACT In this paper, we present the structural properties and morphology of galaxies in the central region of the Coma Cluster brighter than 19.5 mag in the F814W band from the HST/ACS Coma Cluster Treasury Survey. Using mainly spectroscopic redshifts, we find 132 members from our sample of 219 galaxies. In our sample of 132 members, we find 51 non-dwarfs and 81 dwarfs, and amongst our 32 non-members, we find 4 dwarfs and 28 non-dwarfs. We do not have redshifts for the remaining 55 galaxies. We present bulge–disc decomposition of the sample using galfit and obtain parameters for our sample. Using visual inspection of residuals, we do a morphological classification of the galaxies. We studied the relation of morphological types with Bulge to Total Light Ratio (B/T), colour–magnitude relation (CMR), Sérsic index (n), Kormendy relation, and cross-correlations between these parameters for the bulges and galaxies. This work helps us understand important relations between various parameters like B/T, colour, and n as well as insights into the merger history of these galaxies in terms of their positions in the Kormendy Diagram and their Sérsic indices. We find that there are significantly more E/SO, SOs galaxies in the member population compared to non-members.