Dwarf Galaxies: The Nexus of Dark Matter and Chemical Evolution

The Local Group’s dwarf galaxies are near enough for exquisitely detailed, resolved stellar spectroscopy and diverse enough to conduct experiments on dark matter and chemical evolution.  I have collected medium-resolution spectra for thousands of stars in many dwarf galaxies in the Local Group.  Innovative techniques applied to these spectra recover velocities precise to a few km/s and detailed abundances precise to 0.1 dex.   Although Milky Way satellites and field dwarf galaxies are different in many ways, their velocity dispersions show that both types of galaxy pose a serious challenge to cold dark matter.  Both types also obey the same mass-metallicity relation despite the large diversity of star formation histories and detailed abundance ratios.

Cody Hall

Evan Kirby (UC Irvine)

February 18, 2014
14:00 - 15:00