Ram pressure stripping in elliptical galaxies: II. magnetic field
  effects
  We investigate the effects of magnetic fields and turbulence on ram pressure
stripping in elliptical galaxies using ideal magnetohydrodynamics simulations.
We consider weakly-magnetised interstellar medium (ISM) characterised by
subsonic turbulence, and two orientations of the magnetic fields in the
intracluster medium (ICM) - parallel and perpendicular to the direction of the
galaxy motion through the ICM. While the stronger turbulence enhances the ram
pressure stripping mass loss, the magnetic fields tend to suppress the
stripping rates, and the suppression is stronger for parallel fields. However,
the effect of magnetic fields on the mass stripping rate is mild. Nevertheless,
the morphology of the stripping tails depends significantly on the direction of
the ICM magnetic field. The effect of the magnetic field geometry on the tail
morphology is much stronger than that of the level of the ISM turbulence. The
tail has a highly collimated shape for parallel fields, while it has a
sheet-like morphology in the plane of the ICM magnetic field for perpendicular
fields. The magnetic field in the tail is amplified irrespectively of the
orientation of the ICM field. More strongly magnetised regions in the ram
pressure stripping tails are expected to have systematically higher metallicity
due to the strong concentration of the stripped ISM than the less magnetised
regions. Strong dependence of the morphology of the stripped ISM on the
magnetic field could potentially be used to constrain the relative orientation
of the ram pressure direction and the dominant component of the ICM magnetic
field.
