A&A Colloquium: Alyson Brooks (Rutgers University)

3:30–4:30 pm ERC 161

Host: Andrey Kravtsov

Alyson Brooks (Rutgers University) "Darkness on the Edge of Town: Interpreting Newly Discovered Dwarf Galaxies"

New observational surveys (e.g., Rubin's LSST, WALLABY) are enabling the discovery of hundreds of nearby dwarfs galaxies. Are we theoretically ready for what the surveys will find? Given their shallow potential wells, dwarfs are excellent probes of star formation and feedback processes. In the last decade, it has generally become accepted that a proper treatment of gas and stars (baryonic matter) can alleviate the small scale problems in Cold Dark Matter (CDM) galaxy formation theory. However, the models of energetic feedback from stars that have solved some of the tensions in CDM are now running into trouble solving new problems, specifically the "diversity of rotation curves" problem. In this talk, I’ll outline a campaign to simulate the largest suite of dwarf galaxies to date, in environments both near the Milky Way and further afield, in order to interpret upcoming observations. I demonstrate that these galaxies predict a difference in the stellar-to-halo mass relation of dwarf galaxies as a function of distance from a Milky Way-mass galaxy, which naturally produces lower quenching rates, higher HI fractions, and bluer colors for more isolated dwarf galaxies. Additionally, the simulated dwarfs seem to show the full range of diversity in their rotation curves, even within CDM. I will highlight early results exploring the origin of diversity in CDM.

Event Type


May 1