Barred Galaxies in the Coma Cluster

We use ACS data from the HST Treasury survey of the Coma cluster (z˜0.02) to study the properties of barred galaxies in the Coma core, the densest environment in the nearby Universe. This study provides a complementary data point for studies of barred galaxies as a function of redshift and environment. From ˜470 cluster members brighter than MI = -11 mag, we select a sample of 46 disk galaxies (S0-Im) based on visual classification. The sample is dominated by S0s for which we find an optical bar fraction of 47±11% through ellipse fitting and visual inspection. Among the bars in the core of the Coma cluster, we do not find any very large (abar>2 kpc) bars. Comparison to other studies reveals that while the optical bar fraction for S0s shows only a modest variation across low-to-intermediate density environments (field to intermediate-density clusters), it can be higher by up to a factor of ˜ 2 in the very high-density environment of the rich Coma cluster core