Astronomy Colloquium

The inflow and outflow of gas through the circumgalactic medium (CGM) in isolated galaxies and the intracluster medium (ICM) in groups and clusters regulates the growth of galaxies over cosmic time.   Observations reveal a complex multi-phase structure for the gas in the CGM and ICM.  In this talk I will describe some of the key physical processes that influence the structure of gas in the CGM and ICM, including the role of thermal instability in both the hydrostatic halo and galaxy outflows.  I will also describe implications of these results for observational diagnostics of the CGM and ICM and the thermal histories of galaxies, groups, and clusters.