  Numerical simulations of the dynamical friction suffered by a Galactic center
star cluster harboring an intermediate-mass black hole (IMBH) have been
performed. Gerhard has suggested that dynamical friction, which causes a
cluster to lose orbital energy and spiral in toward the Galactic center, may
explain the presence of a cluster of very young stars in the central parsec,
where star formation might be prohibitively difficult because of strong tidal
forces. However, numerical simulations by Kim & Morris showed that this is only
possible if the cluster initially has an extremely dense core. Hansen &
Milosavljevic recently suggested that the presence of an IMBH in the cluster
core might stabilize the core against tidal disruption during the inspiral
through dynamical friction, and thus might easily deliver young stars down to
the central parsec. We find that the presence of an IMBH does lower the minimum
initial core density required to transport young stars down to the central
parsec, but this is possible only when the mass of the IMBH is at least ~10% of
the total cluster mass. This fraction is significantly higher than that
estimated by Portegies Zwart & McMillan with numerical simulations of IMBH
formation by successive merging of stars in the cluster core, so it does not
appear that a realistic IMBH can help transport young stars into the central
parsec.
