The Fast and the Furious: High Velocity Clouds Crashing Through Galaxies
Prof. Robin Shelton
University of Georgia
A multitude of massive, fast-moving gas clouds swarms about our Galaxy. Some of the clouds, such as the Smith Cloud, are poised to collide with our Galaxy’s disk with speeds in excess of 100 km/sec and masses in excess of a million times the mass of the Sun. The upcoming collision between the Smith Cloud and the disk will have the energy of hundreds of supernova explosions. It will be disruptive, but will also be a source of fresh material for our Galaxy. Additional clouds, called high velocity clouds (HVCs) are currently in the halo and circumgalactic regions, where they interact with the lower density environment of our Galaxy. Similar clouds have been observed near other large spiral galaxies. My group has been computationally modeling HVCs, with the goal of determining how HVCs interact with galaxies. In various simulations, we examine their collisions with the disk or their passage through the halo and circumgalactic regions on timescales of hundreds of millions of years. As fits the case, we consider the effects of dark matter, magnetic fields, and time-dependent ionization and recombination of the metal atoms. In this presentation, I will show how HVCs evolve as they travel into the galaxy and collide with the disk and how they seed the halo/circumgalactic medium with warm gas while also condensing and capturing environmental material.
Hosted by Prof. Lehner
All interested persons are invited to attend remotely—email physics@nd.edu for information.