The Physics department colloquia are usually on Friday afternoons at 3 pm in Room 135. Coffee and cookies are served at 2:45 pm in the same room. Anyone is welcome.

Galaxy Transformation and the Evolution of the Gas Content of Galaxy Groups
Dr. Eric M. Wilcots, Dept. of Astronomy, University of Wisconsin (Madison)
Physics – Room 135

The current state of our understanding of the nature of the baryon content of galaxy groups, derived largely from a large body of X-ray observations, leaves us with two key questions. First, what are the relative fractions of the hot, warm/hot, and neutral gas in galaxy groups, and how is each phase distributed within groups? Second, how has the baryon content of galaxy groups evolved over time and what is its relationship to the dynamical evolution of the group?

The results from a number of investigations of the HI content and deep searches for diffuse synchrotron emission in groups are now shedding light on the evolution of the baryon content of galaxy groups and what impact those baryons have on the evolution of the resident galaxies. I will review our new results tracing the impact of the intergalactic on the evolution of galaxies in groups and measurement of the baryon content of groups using bent double radio sources.