A revised calculation of the bremsstrahlung cross-section in the high magnetic field of pulsars

It has been postulated that electron bremsstrahlung in a strong external magnetic field is the dominant radiation mechanism within the accretion plasma near the magnetic polar regions of binary X-ray sources. Earlier works on the cross section for such a process proved to be unsatisfactory. The present work uses the simple structure of the propagator obtained in a previous calculation for mildly relativistic electrons occupying no more than the first few Landau levels. Particular emphasis is put on the integration over the possible range of momentum transfer during a single collision with the ion. Typical behaviour for two linear polarization modes is illustrated for forward and backward electron scattering. It is found that the previously predicted behaviour at low frequencies for the two modes is only correct in the limit of weak field and large momentum transfer. At higher frequencies resonances are present irrespective of the polarization of the emitted radiation. (orig.)