MIT Astrophysics Colloquium
The ultra-faint dwarf galaxies discovered around the Milky Way and M31 include objects with less than one millionth of the Milky Way’s own luminosity. The detailed properties of these puny satellites, as well as the remnants thereof, are being used to test dark matter+galaxy formation models. To fully exploit the Milky Way’s halo to test such models requires a stellar halo map that is as complete and unbiased as possible. I will discuss how wide-field surveys (such as UKIDSS, DES, and LSST) will contribute to mapping the Milky Way out to its virial radius. I will focus on efforts to learn about ultra-faint dwarf galaxies and their relationship with dark matter halos, and early results from a program to map the Milky Way to its outermost regions using M giant stars.