Kinematics of Outer Halo Globular Clusters in M31
  We present the first kinematic analysis of the far outer halo globular
cluster (GC) population in the Local Group galaxy M31. Our sample contains 53
objects with projected radii of ~20-130 kpc, of which 44 have no previous
spectroscopic information. GCs with projected radii >30 kpc are found to
exhibit net rotation around the minor axis of M31, in the same sense as the
inner GCs, albeit with a smaller amplitude of 79 +/-19 km/s. The
rotation-corrected velocity dispersion of the full halo GC sample is 106 +/-12
km/s, which we observe to decrease with increasing projected radius. We find
compelling evidence for kinematic-coherence amongst GCs which project on top of
halo substructure, including a clear signature of infall for GCs lying along
the North-West stream. Using the tracer mass estimator, we estimate the
dynamical mass of M31 within 200 kpc to be M_M31 = (1.2-1.5) +/- 0.2 x 10^12
M_sun. This value is highly dependent on the chosen model and assumptions
within.
