Galaxy Evolution in Cluster Cores
Galaxies are found in a vast range of environments; populating voids, the field, groups and clusters. Those at the center of massive clusters are subject to a particularly extreme environment and, as such, are a perfect laboratory to study the interactions between galaxies and gas reservoirs. Near the cluster core, densely packed galaxies are swirling around the immense gravitational potential while in the center is usually a large red galaxy, often the most luminous of the cluster. These Brightest Cluster Galaxies (BCGs) are bathed in the hot X-ray emitting cluster gas, and are surrounded by massive stellar halos - perhaps their own (in the case of a cD galaxy) or that of the cluster (the IntraCluster Light, ICL). In this talk I will discuss my observational studies of massive red cluster galaxies from the point of view of their retirement from beyond the red and dead. The motivation is to discover to what level the renewed activity in and around these galaxies might be linked to the physical properties of the cluster as a whole. We find that cluster properties are paramount to the detection of emission lines in a BCG, that when there is line emission, both AGN and recent star formation are important, and that the role of close companions - especially potential minor mergers - can be an important component for the buildup of stellar mass at the cluster core. I will end by discussing my plans to use the WIYN telescope in the near future to measure the ages and metallicities of the stars and gas surrounding BCGs. This will provide the data necessary to build an evolutionary history connecting the BCG, nearby companions, and ICL of the cores of massive clusters.
Date: Lundi, le 19 novembre 2012 Heure: 14:30 Lieu: Université Laval Pavillon Alexandre-Vachon, VCH1661