Magnetorotation-induced pulsar recoils

We propose a new mechanism for pulsar kicks, which is magnetohydrodynamically-induced kick. We carry out two-dimensional numerical simulations on the core-collapse of a massive star with differential rotation and initially large magnetic fields which have equatorially asymmetric dipole-like configuration. As a result of the computations, we get transient large kick velocities which are up to 500 km/s. However, these large velocities are soon damped since surrounding matter prevent proto-neutron-stars from moving away and finally no substantial kicks are produced. This may be a crucial problem for all pulsar kick computations.