Physics Colloquium: The circumgalactic medium: What is it and how does it affect the evolution of galaxies?

Abstract: 

While galaxies stand out as the brightest lights observed by telescopes, most of the normal matter in the Universe is in diffuse gas outside of galaxies. The circumgalactic medium, or CGM, refers to the massive gas halos surrounding galaxies. In addition to containing large quantities of matter, the CGM is where some of the main processes driving and regulating galaxy formation operate. This talk will begin with a broad introduction to the CGM, then focus on recent results concerning a key phase transition in the CGM, known as "virialization," during which the CGM transforms from cold to hot. I will discuss theoretical predictions, based on a combination of analytic modeling and simulations, for how the CGM virializes. I will also summarize results on the connections between CGM virialization and the evolution of galaxies, including the emergence of disk galaxies similar to the Milky Way.

Event Organizer: Prof. Amiel Sternberg