Theory and simulations of relativistic particle motions in a magnetosonic shock wave

摘要

The motions of relativistic particles in a magnetosonic shock wave propagatingobliquely to an external magnetic field are studied. In the zeroth-ordertheory, particles continue to move nearly parallel to the external magnetic field inthe shock transition region, when the shock speed is close to c cos θ, where c is thespeed of light and θ is the propagation angle. Perturbations to this zeroth-ordermotion are also analyzed for positrons and ions. The perturbation frequency ofpositrons is ω ? Ωp0γ?1 and that of ions is ω ? Ωi0γ?1/2, where Ωp0 and Ωi0 arethe non-relativistic gyrofrequencies of positrons and of ions, respectively, and γis the Lorentz factor. These theoretical predictions are confirmed with numericalsimulations.