“Physical Conditions of Diffuse Ionized Gas”

Dr. Matt Haffner
University of Wisconsin Madison
The Wisconsin H-Alpha Mapper (WHAM) has been exploring optical emission from a variety of diffuse ionized sources for the last decade from Kitt Peak, AZ. In this talk, I will focus on what WHAM has been contributing to our knowledge about the physical conditions of the diffuse Galactic plasma, the Warm Ionized Medium (WIM). Most recently, an investigation of the distribution of emission measures from our H-alpha survey led us to combine our observations with MHD models to reveal some of the deepest insight yet into the properties of the turbulence and density structure of the WIM. WHAM is also providing key measurements, maps, and constraints on emission from ionized gas toward more discrete gas structures. I will touch on how it is contributing to the study of intermediate- and high-velocity clouds; large angular-scale H II regions around nearby O- and B-stars; and faint, isolated ionized nebulae--many previously undetected--at moderate to high Galactic latitudes. This year, we are moving the facility to CTIO to finish the all-sky H-alpha survey and begin detailed studies of southern targets.