Galaxy evolution in groups and clusters in a hierarchical Universe

Seminar | October 2 | 1:10 p.m. | B1 Hearst Field Annex

Speaker/Performer: Andrew Wetzel, Yale

Sponsor: Department of Astronomy

Satellite galaxies in groups and clusters play a critical role in the picture of galaxy evolution. As many as a third of all galaxies are satellites, and satellite star formation quenching is the dominant process in building the red-sequence population at low stellar mass. I will present an observational and theoretical investigation into the evolution of star formation in satellite galaxies, using the Sloan Digital Sky Survey to examine satellites across a wide range of host halo masses, from massive clusters to the lowest mass dwarf galaxy groups in the local Universe. I will place these results in a fully cosmological context using a high-resolution simulation to track satellite orbits and infall times, showing that satellite star formation histories follow a delayed-then-rapid quenching scenario. Using satellite orbital histories, I also will test various physical mechanisms thought to play a role in quenching satellites. Finally, I will examine the curious evolution of satellites that orbit beyond their host halo's virial radius.

Event Contact: rhelgens@astro.berkeley.edu, 510-642-5275