Physical Society Colloquium

Mapping the Milky Way's Dark Matter Halo with Gaia

Mariangela Lisanti

Department of Physics
Princeton University

The Gaia mission is in the process of mapping nearly 1% of the Milky Way's stars. This data set is unprecedented and provides a unique view into the formation history of our Galaxy and its associated dark matter halo.  I will review results based on the most recent Gaia data release, demonstrating how the evolution of the Galaxy can be deciphered from the stellar remnants of massive satellite galaxies that merged with the Milky Way early on.  The recent advancements in our understanding of the Galaxy's evolution suggest that a component of the local dark matter is not in equilibrium, as typically assumed, and instead exhibits distinctive dynamics. The updated dark matter map built from the Gaia data has ramifications for direct detection experiments, which search for the interactions of these particles in terrestrial targets.