Oct 28, 2013
Rukmani Vijayaraghavan, University of Illinois
"Science Lunch Talk: Rukmani Vijayaraghavan "Transforming Galaxies in Groups and Clusters""
Abstract: Galaxies in groups and clusters are `red and dead' compared to field galaxies. Galaxy groups can `pre-process' galaxies before they fall into more massive clusters, and galaxies that fall in as part of a group can remain coherent for up to one orbital period. In our work, we show the importance of group environments on influencing cluster galaxy evolution, in particular, the enhanced merger rates in groups, the removal of gas due to ram pressure in the IGM, and tidal truncation of galaxies in a group. Galaxies outside cluster virial radii are known to have star formation suppressed relative to the field, and we show that gas removal in group environments can explain this phenomenon. I will also talk about a group-cluster merger and its impact on galaxy evolution -- coherent galaxy velocities within an infalling group can lead to increased galaxy interaction rates, and the merger shock results in increased ram pressure on group galaxies.