The Eating Habits of the Milky Way Halo

The Milky Way (MW) galaxy is a cannibal; throughout its lifetime it
devours hundreds of smaller "dwarf" galaxies. Observable memories of
this voracious eating habit are splayed out in a vast stellar halo,
which extends out to thousands of light years from the Galactic
centre.

In the next decade, we will witness an explosion in the number of
dedicated observational surveys of the MW halo. Our current
observational view of the halo is, at best, limited to 4 dimensions
--- 3 positions, and 1 velocity component along the
line-of-sight. However, we are now entering the era of "Galactic
astrometry", where upcoming missions such as Gaia and the Large
Synoptic Survey Telescope (LSST) will provide exquisite measurements
of the transverse motions of halo stars. The addition of the
transverse velocity components will transform our view of the halo
into 6 dimensions. This game-changing 6D dataset will be essential in
order to decipher the eating habits of our Galaxy.

This project will couple observational survey data with
state-of-the-art models of galaxy formation in order to unravel the
assembly history of the MW. Mock observations of simulated stellar
halos will be developed that cater towards high-impact observational
surveys such as Gaia and LSST. These mocks will be vital in order to
exploit the exquisite observational data to its full potential, and
will provide a testable theoretical framework that can be directly
compared to observations. The student will use several different
datasets to compare with the mocks, including the latest data releases
from the Gaia mission.