This colloquium was originally recorded at the Aspen Center for Physics on Thursday, September 12, 2024. Our Colloquium series is for physicists, by physicists. Please see our "Public Lecture" playlists for videos intended for the general public.
We now know that the typical galaxy is surrounded by a spatially extended circumgalactic medium (CGM) that serves as both its long-term fuel reservoir and garbage dump. While great progress has been made in understanding how galaxies grow and change over time, a self-consistent explanation for the physical origins of this CGM remains elusive. Understanding the physics and chemistry of circumgalactic gas is essential to identify its role in the baryon cycle - the interplay and exchange of gas between galaxies and their environments - and its impact on galaxy evolution. Using high-quality and high-resolution spectroscopy from ground and space, we can now figure out the detailed physical properties and chemical makeup of the CGM of individual galaxies. I will discuss the evidence for multitude physical origins of the CGM in different galaxy populations. I will end by discussing the prospects for future discoveries enabled by studying circumgalactic physics and chemistry, using spatially resolved observations of the CGM obtained with the next generation of space and ground-based telescopes.
Fakhri Zahedy is a faculty member at the Department of Physics, University of North Texas. A lifelong observational astronomer, he obtained his BS degree in Physics at the Massachusetts Institute of Technology in 2013. and his PhD in Astronomy and Astrophysics at the University of Chicago in 2019. He was awarded a Carnegie Postdoctoral Fellowship at the Carnegie Science Observatories, a position he held from 2019 to 2023. He is interested in galaxy evolution, particularly in a better understanding of how the gaseous reservoir of a galaxy determines the course of its evolution over cosmic time.
18 сен 2024
