BONDI ACCRETION ONTO MAGNETIC DIPOLE
Authors: Yu. M.
Toropin, O. D. Toropina, V. V. Savelyev, M. M. Romanova, V.M. Chechetkin , R. V. E. Lovelace
Quasi-spherical supersonic (Bondi-type) accretion to a star with a
dipole magnetic field is investigated using resistive magnetohydrodynamic simulations. A
systematic study is made of accretion to a non-rotating star, while sample results for a
rotating star are also presented. A new stationary subsonic accretion flow is found with a
steady rate of accretion to the magnetized star smaller than the Bondi accretion rate.
Dependences of the accretion rate and the flow pattern on the magnetic momentum of the
star and the magnetic diffusivity are presented. For slow star's rotation the accretion
flow is similar to that in non-rotating case, but in the case of fast rotation the
structure of the subsonic accretion flow is fundamentally different and includes a region
of ``propeller'' outflow. The methods and results described here are of general interest
and can be applied to systems where matter accretes with low angular momentum.