16 research outputs found
Spherical Bondi accretion onto a magnetic dipole
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.Comment: 15 pages, 15 figures, used emulapj.st