Oldies but Goodies: Old Hypervelocity Stars and RR Lyrae as Probes of
the Inner and Outer Milky Way
Juna Kollmeier (Carnegie Observatories)
The Milky Way provides an opportunity for a close-up investigation of
the complex processes of galaxy and star formation. I will discuss
recent efforts to do this by using rare, but important, probes of
these phenomena. In the first portion of the talk I will present
results on hypervelocity stars primarily from the Sloan Digital Sky
Survey. The distribution of these stars, in physical properties and
in space, allows us to place interesting limits on star formation and
dynamics at the Galactic Center as well as the possibility to
constrain the shape of the Milky Way's dark matter halo. I will
discuss progress we have made toward these goals. In the second
portion of the talk, I will discuss how one can use RR Lyrae stars to
probe the outer halo of the Milky Way and find new and distant
substructures which are difficult to probe by other means. Our recent
confirmation of a distant structure in RR Lyrae stars highlights
the power of this approach to unraveling the outer halo and showcases
exciting possibilities for future all-sky time-domain surveys.
