E+A Galaxy Candidates in and around the Leo Cluster

Abstract

E+A galaxies are post-starburst galaxies that have undergone a recent, complete quenching of star formation. We have analyzed a color-constrained sample of galaxies from the Sloan Digital Sky Survey within a 77.′5 radius of the center of the Leo cluster of galaxies (A1367; J2000 11:44:36.5 + 19:45:32) within 3000 km s−1 of Leo’s redshift of z = 0.022 to identify and survey the E+A galaxy candidates in the cluster. Within this sample, we classified 52 of these galaxies as E+A galaxy candidates based on their spectral shapes, u–r color, lack of Hα emission, and higher-order hydrogen Balmer absorption. We further subdivide this group into “blue” and “green” E+A candidates. Our results show that the E+A galaxy candidates are distributed across the northwest and southeast subclusters of Leo, possibly as a result of merging between the two subclusters.