Probing the Baryon Content of Galaxy Groups: A Radio Perspective

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. I will review recent results from these surveys and present a roadmap for future observations.