Abstract
We use a distribution function analysis to estimate the mass of the Milky Way
out to 100 kpc using a large sample of halo stars. These stars are compiled
from the literature, and the vast majority (~98%) have 6D phase-space
information. We pay particular attention to systematic effects, such as the
dynamical influence of the Large Magellanic Cloud (LMC), and the effect of
unrelaxed substructure. The LMC biases the (pre-LMC infall) halo mass estimates
towards higher values, while realistic stellar halos from cosmological
simulations tend to underestimate the true halo mass. After applying our method
to the Milky Way data we find a mass within 100 kpc of M(< 100 kpc) = 6.07 +/-
0.29 (stat.) +/- 1.21 (sys.) x 10^11 M_Sun. For this estimate, we have
approximately corrected for the reflex motion induced by the LMC using the
Erkal et al. model, which assumes a rigid potential for the LMC and MW.
Furthermore, stars that likely belong to the Sagittarius stream are removed,
and we include a 5% systematic bias, and a 20% systematic uncertainty based on
our tests with cosmological simulations. Assuming the mass-concentration
relation for Navarro-Frenk-White haloes, our mass estimate favours a total
(pre-LMC infall) Milky Way mass of M_200c = 1.01 +/- 0.24 x 10^12 M_Sun, or
(post-LMC infall) mass of M_200c = 1.16 +/- 0.24 x 10^12 M_Sun when a 1.5 x
10^11 M_Sun mass of a rigid LMC is included.