All-Moscow Seminar of Astrophysicists
(ASA)

annotation of talk
O.D.Toropina (Space Research Institute), M.M.Romanova (Cornell University)
Propagation of magnetized neutron stars through the interstellar medium


We discuss the propagation of magnetized, isolated old neutron stars through the interstellar medium. We performed axisymmetric, non-relativistic magnetohydrodynamic (MHD) simulations of the propagation of a non-rotating star with dipole magnetic field aligned with its velocity through the interstellar medium (ISM).

We consider two cases:

  1. where the accretion radius Racc is comparable to the magnetic standoff distance or Alfven radius RA and gravitational focusing is important;
  2. where Racc << RA and the magnetized star interacts with the ISM as a "magnetic plow", without significant gravitational focusing.
The magnetosphere of the star represents an obstacle for the flow, and a shock wave stands in front of the star. Magnetic field lines are stretched downwind from the star and form a hollow elongated magnetotail. Reconnection of the magnetic field is observed in the tail which may lead to acceleration of particles. Similar powers are estimated to be released in the bow shock wave and in the magnetotail. The estimated powers are, however, below present detection limits. Results of our simulations may be applied to other strongly magnetized stars, for example, white dwarfs and magnetic Ap stars.