Resolving Cool Circumgalactic Gas Flows: Insights into the Physics of Galaxy Formation

Modern galaxy formation theory suggests that large-scale outflows of gas driven by processes related to star formation play a crucial role in regulating the stellar mass growth of galaxies. These flows are likewise invoked to feed the massive reservoirs of diffuse gas that are known to surround luminous galaxies like the Milky Way. However, the energetics and physical impact of these outflows remain poorly constrained. I will discuss a new observational technique that has now been used to map the spatial extent and density distribution of large-scale galactic outflows in unprecedented detail. Observational constraints on these quantities are required to complete our understanding of the processes that drive galaxy formation.