Probing dark matter in the Milky Way on small and large scales with stellar streams

by Denis Erkal (Surrey, UK)

Tuesday 11 Feb 2025, 15:00 → 16:30 Europe/Zurich

ON line only (CERN)

Stellar streams form as dwarf galaxies and globular clusters tidally disrupt around their host galaxy. To date, more than 100 streams have been detected around our Galaxy. In this talk, I will begin with an overview of how streams form. I will then demonstrate how stellar streams are sensitive to the small-scale distribution of dark matter in the Milky Way. I will show observations of stellar streams and explain how we can use these to probe the population of dark matter subhaloes in the Milky Way and constrain the properties of the dark matter particle. I will then explain how we can use stellar streams to probe the large-scale distribution of dark matter in the Milky Way. I will show how they can be used to measure the gravitational potential of our Galaxy, and how the Large Magellanic Cloud has a large effect on many streams in the Milky Way. In particular, I will focus on one of the best-measured streams in the Milky Way, the Orphan-Chenab stream, and show how we can it to measure the shape of the Milky Way's dark matter halo and the mass of both the Milky Way and the Large Magellanic Cloud. Finally, I will show that the Orphan-Chenab stream can be used to infer how much dynamical friction the Large Magellanic Cloud has experienced and discuss how this could be used to constrain the nature of dark matter.

 

zoom link : https://universiteitleiden.zoom.us/my/alessandrasilvestri?pwd=NiVtRIahWw8LjpeKJYfdWLBmbA9UtY.1