On the Edge: the relation between stellar and dark matter halos of Milky Way-mass galaxies
Abstract
I will discuss the predictions of the Cold Dark Mater model on the
build-up of stellar and dark matter halos of Milky Way-mass galaxies. I
will show that the stellar and dark matter halos have a common origin to
a significant extent — the stellar halo is composed primarily of 2-3
past mergers, which also contribute ~30% of the dark matter halo mass.
Past mergers leave phase-space features, such as shells, in the stellar
halo, which have corresponding features in the dark matter. The
outermost shell defines the “edge” of the stellar halo and is related to
the dark matter halo mass, splashback radius and recent assembly
history. Finally, I will discuss how stellar haloes can be used to probe
the nature of dark matter.