Speaker
Description
As luminous tracers of the smallest observationally accessible dark matter halos, faint satellite galaxies orbiting the Milky Way (MW) have the potential to dramatically improve our understanding of dark matter microphysics. However, the confounding effects of baryonic physics on halo abundances and galaxy formation have made the interpretation of the observed MW satellite population unclear. I will describe a forward model for the MW satellite population based on high-resolution zoom-in simulations that marginalizes over these astrophysical effects and accounts for the relevant numerical and observational uncertainties. Combined with newly derived observational selection functions and detailed modeling of the satellite population associated with the Large Magellanic Cloud, this method yields constraints on a variety of dark matter models including sterile neutrinos, ultra-light axions, and interacting dark matter that are competitive with Lyman-alpha forest and strong gravitational lensing measurements. I will highlight limits on the DM-baryon scattering cross section in WIMP-like scenarios that improve upon CMB and Lyman-alpha forest analyses by several orders of magnitude.
