Joint Astrophysics Colloquium

How Do Galaxies in Massive Clusters Form Their Stars?

Kim-Vy Tran

Texas A&M University/University of Zurich

Galaxy clusters are the largest gravitationally bound systems in the universe and include the most massive galaxies in the universe; this makes galaxy clusters ideal laboratories for disentangling the nature versus nurture aspect of how galaxies evolve. Understanding how galaxies form and evolve in clusters continues to be a fundamental question in astronomy. The ages and assembly histories of galaxies in rich clusters test both stellar population models and hierarchical formation scenarios. Is star formation in cluster galaxies simply accelerated relative to their counterparts in the lower density field, or do cluster galaxies assemble their stars in a fundamentally different manner? To answer this question, I review results from our Spitzer/MIPS Infra-Red Cluster Survey (SMIRCS; 0<1) and present first results for one of the most distant clusters yet discovered at a look-back time of nearly 10 billion years (z=1.62).