Dynamical friction in a magnetized gas

Abstract

When a gravitating point mass moves subsonically through a magnetized and isothermal medium, the dynamical structure of the flow can be studied far from the mass using a perturbation analysis. Here, we present analytical solutions for the first-order density and the velocity perturbations. The validity of our solutions is restricted to the cases where the Alfvén 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. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.