Dynamically Extreme Stellar and Galactic Populations in the Via Lactea II Cosmological Simulation and Their Observable Counterparts

Maureen Teyssier, Rutgers University

We describe dynamically unusual populations with observable counterparts (backsplash galaxies, wandering stars and high velocity stars) in the environment in and outside of a Milky Way-like object. Analysis of VLII halo histories and z=0 distribution allows us to distinguish which Local Group field galaxies may have passed through the virial volume of the Milky Way. We find it likely that Tucana, Cetus, NGC3109, SextansA, SextansB, Antlia, NGC6822, Phoenix, LeoT, and NGC185 have passed through the Milky Way. Several of these galaxies contain signatures in their morphology, star formation history, and/or gas content, that are indicative of evolution seen in simulations of satellite/parent galactic interactions. We use the histories of VLII particles that are far outside Rvir at z=0 to estimate the likelihood of observing inter-galactic supernovae in current and near-future large-scale time-domain surveys. Finally, we ask whether a merger history similar to what is seen in VLII should lead to a significant population of old high-velocity stars associated with dark matter flows.