Departmental Colloquium
- Title
- The Dark Side of H2 in the Galaxy: The Empire Strikes Back
- Guest Speaker
- Prof. Loris Magnani
- Guest Affiliation
- Department of Physics and Astronomy, The University of Georgia
- When
- Thursday, January 19, 2017 3:30 pm - 4:30 pm
- Location
- Physics Auditorium (202)
- Details
- The idea that substantial molecular gas is present in the interstellar medium but is not detectable by the CO(1-0) emission line has become fairly prevalent in the last decade. This component hasbecome known as "dark gas", a term first suggested in a paper describing its properties and extent by Grenier, Casandjian and Terrier (2005). Their main conclusion is that the dark gas mass in the Milky Way is comparable to the molecular mass detected by CO(1-0) emission. More recent studies seem to corroborate this conclusion. A key element in deciding whether molecular gas may be dark or not depends on thesensitivity of the CO observations. Here we present very sensitive CO, OH, and CH observations of the outer regions of diffuse molecular gas which show that most of the dark molecular gas can be spectroscopically detected with sensitive enough observations.