Properties of the Remnant Clockwise Disk of Young Stars in the Galactic
  Center
  We present new kinematic measurements and modeling of a sample of 116 young
stars in the central parsec of the Galaxy in order to investigate the
properties of the young stellar disk. The measurements were derived from a
combination of speckle and laser guide star adaptive optics imaging and
integral field spectroscopy from the Keck telescopes. Compared to earlier disk
studies, the most important kinematic measurement improvement is in the
precision of the accelerations in the plane of the sky, which have a factor of
six smaller uncertainties (~10 uas/yr/yr). We have also added the first radial
velocity measurements for 8 young stars, increasing the sample at the largest
radii (6"-12") by 25%. We derive the ensemble properties of the observed stars
using Monte-Carlo simulations of mock data. There is one highly significant
kinematic feature (~20 sigma), corresponding to the well-known clockwise disk,
and no significant feature is detected at the location of the previously
claimed counterclockwise disk. The true disk fraction is estimated to be ~20%,
a factor of ~2.5 lower than previous claims, suggesting that we may be
observing the remnant of what used to be a more densely populated stellar disk.
The similarity in the kinematic properties of the B stars and the O/WR stars
suggests a common star formation event. The intrinsic eccentricity distribution
of the disk stars is unimodal, with an average value of <e> = 0.27 +/- 0.07,
which we show can be achieved through dynamical relaxation in an initially
circular disk with a moderately top-heavy mass function.
