Princeton University Dark Cosmos Seminar

The identity of dark matter is one of the biggest outstanding questions in astrophysics today. The smallest galaxies in the universe, dwarf galaxies, are powerful probes of its identity, as they are composed predominantly of dark matter.  However, despite their lack of baryons, their galaxies are heavily shaped by their dark matter halos.  I show that in EDGE, a high resolution, cosmological hydrodynamic simulation suite of dwarf galaxies, we find that key galaxy properties such as stellar mass, size, and metallicity, are affected by halos' growth histories. This implies that dark matter models with growth histories that differ from cold dark matter may be more tightly constrained by including these baryonic effects.  As an example, I show how dwarf galaxies in the new EDGE warm dark matter simulations are not just less abundant but---as the halos form later, they are also fainter and larger, implying that constraints based on abundance or luminosity functions may be loosened. Ultimately, the most powerful constraints may come from jointly constraining multiple dwarf properties affected by dark matter growth histories.  I show that dark matter constraints based on the Milky Way satellite galaxies can be tightened by considering not just their abundance but also their kinematics.  To end, I preview some exciting new results from EDGE that that indicate that the faintest dwarf galaxies may share properties of globular clusters, and their implications for dark matter constraints.