Events on Thursday, May 22nd, 2025
- R. G. Herb Condensed Matter Seminar
- Title to be announced
- Time: 10:00 am
- Place: 5280 Chamberlin Hall
- Speaker: Miguel Morales
- Host: Matthew Otten
- Astronomy Colloquium
- Small-Scale Structure of the "Dark ISM"
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Joanne Dawson, Macquarie University
- Abstract: It is now known that a significant fraction of the Milky Way ISM resides in a so-called "dark" phase, usually defined as a mixture of cold, optically thick HI and diffuse molecular hydrogen with densities that are insufficient to form and shield CO. I will present a brief overview of the so-called "Dark ISM" -- where it resides, how much there is, and its characteristic properties. I will then focus on two aspects of structure in the dark gas: (1) AU-scale structures in the cold atomic medium, including their possible implications in measuring the fraction of cold/opaque HI, and (2) underlying structure in CO-dark molecular gas that can give rise to very broad, very weak molecular spectral features in OH and HCO+. I will introduce two ongoing observational experiments that may further constrain both of these phenomena.
- Host: Snezana Stanimirovic