Abstract
We present the first detailed physically-based thermodynamic model of
the Galaxy as obtained from high-resolution kinematical data from the
inner stellar halo. We interpret the observed distribution of Hyper
Velocity Stars (HVS) as a physical manifestation of the
Maxwell-Boltzmann (M-B) probability distribution expected for a fully
virialized galactic system existing in quasi-equilibrium with its
surroundings. The conventional view is that the HVS sample originates
from chance gravitational encounters that have attained enough speed to
escape the Galaxy. We counter that the HVS population is created by
thermodynamic effects and link the observed mid-disk velocity peak with
the M-B most probable velocity VPeak ≈ Vmp=432 km/s. Most of the HVS
population originates at the Galactic virialization radius of 23 kpc
with the current observed sample reproducing the M-B distribution with
fidelity.