[발표취소] The Relationship Between Bright Galaxies and Their Faint Companions in Galaxy Clusters

Today, it is widely accepted that dense environments tend to accelerate galaxy evolution. However, according to recent studies, the environments where galaxies evolve most considerably are galaxy groups rather than galaxy clusters. In an isolated group, the central host galaxy and its satellites co-evolve and interact with each other; as a result, they tend to have similar properties. Such conformity between host and satellite galaxies are relatively well known in galaxy groups, but it is hardly studied what happens after such galaxy groups merge into a galaxy cluster. Recently, J. H. Lee et al. (2014) have found that the colors of bright galaxies in WHL J085910.0+294957, a galaxy cluster at z = 0.3, show a measurable correlation with the mean colors of faint companions around them, which may be the vestige of infallen groups in the cluster. As a follow-up study, we explore more galaxy clusters, Abell 3659 and Abell 1146 at z ~ 0.1, using deep images obtained from the Magellan (Baade) 6.5-m telescope. Cluster members are selected based on the distributions of color, size and concentration along magnitude and spatial distribution. We investigate the dependence of the mean colors of faint companion galaxies on local environments and the properties of adjacent bright galaxies. After comparing the results with those in J. H. Lee et al. (2014), we discuss the origin of the relationships between bright galaxies and their faint companions based on their dependence on cluster properties.