Binaries migrating in a gaseous disk: Where are the Galactic center
  binaries?
  The massive stars in the Galactic center inner arcsecond share analogous
properties with the so-called Hot Jupiters. Most of these young stars have
highly eccentric orbits, and were probably not formed in-situ. It has been
proposed that these stars acquired their current orbits from the tidal
disruption of compact massive binaries scattered toward the proximity of the
central supermassive black hole. Assuming a binary star formed in a thin
gaseous disk beyond 0.1 pc from the central object, we investigate the
relevance of disk-satellite interactions to harden the binding energy of the
binary, and to drive its inward migration. A massive, equal-mass binary star is
found to become more tightly wound as it migrates inwards toward the central
black hole. The migration timescale is very similar to that of a single-star
satellite of the same mass. The binary's hardening is caused by the formation
of spiral tails lagging the stars inside the binary's Hill radius. We show that
the hardening timescale is mostly determined by the mass of gas inside the
binary's Hill radius, and that it is much shorter than the migration timescale.
We discuss some implications of the binary's hardening process. When the more
massive (primary) components of close binaries eject most their mass through
supernova explosion, their secondary stars may attain a range of eccentricities
and inclinations. Such processes may provide an alternative unified scenario
for the origin of the kinematic properties of the central cluster and S-stars
in the Galactic center as well as the high velocity stars in the Galactic halo.
