Dynamical Friction in a magnetized gas
  When a gravitating point mass moves subsonically through a magnetized and
isothermal medium, the dynamical structure of the flow is studied far from the
mass using a perturbation analysis. Analytical solutions for the first-order
density and the velocity perturbations are presented. Validity of our solutions
is restricted to the cases where the Alfven velocity in the ambient medium is
less than the accretor's velocity. The density field is less dense because of
the magnetic effects according to the solutions and the dynamical friction
force becomes lower as the strength of the magnetic field increases.
