THE SURVIVAL AND DESTRUCTION OF GALAXIES IN DENSE GALAXY CLUSTERS

Galaxies in dense cluster environments are `red and dead' compared to field galaxies. These cluster galaxies are subject to violent astrophysical processes that remove their gas and shut down star formation. Galaxies are subject to tidal forces in the deep potential wells of clusters and interact with other galaxies, resulting in the removal of their stars and gas. The hot X-ray emitting intracluster medium plasma, the dominant baryonic component in clusters, removes hot and cold galactic gas through a ram pressure drag force as well as evaporation due to thermal conduction. These processes do not result in an immediate shut down of star formation: galaxies often go through violent periods when their stripped gas forms stars; in addition, dying stars and active galactic nuclei powered by central supermassive black holes can replenish gas lost from galaxies. While many of these processes have been observed in clusters and their galaxies, a theoretical understanding of the astrophysical processes that remove gas and those that help retain and replenish gas remains elusive. I will present some of our recent results using numerical simulations to quantify the balance between the removal and destruction of galactic gas, and the retention of gas in hostile cluster environments.