The Large Scale Distribution of Gas in the Milky Way
Leo Blitz (University of California, Berkeley)
I review what is generally known about the large-scale distribution of gas in the Milky Way with emphasis on the neutral phases. I will discuss particular issues that are not understood, such as why the atomic gas in the Milky Way (and almost all spiral galaxies) extends considerably beyond the optical radius. I will discuss other structural features that have never been properly explained and speculate on their causes. Finally, I will discuss how some of these features suggest origins in the dark matter distribution.