The Evolution of CosmicRaymediated Magnetohydrodynamic Shocks: A TwoFluid Approach
Abstract
We study the shock structure and acceleration efficiency of cosmicray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a twofluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of planeperpendicular, pistondriven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmicray mediated MHD shocks. The acceleration of cosmicray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.
 Publication:

The Astrophysical Journal
 Pub Date:
 July 1994
 DOI:
 10.1086/174358
 Bibcode:
 1994ApJ...429..748J
 Keywords:

 Cosmic Rays;
 Efficiency;
 Evolution (Development);
 Kinematics;
 Magnetic Fields;
 Magnetohydrodynamics;
 Particle Acceleration;
 Shock Waves;
 Two Fluid Models;
 Viscosity;
 Analytic Functions;
 Numerical Analysis;
 Solutions;
 Steady State;
 Astrophysics;
 ACCELERATION OF PARTICLES;
 ISM: COSMIC RAYS;
 MAGNETOHYDRODYNAMICS: MHD;
 METHODS: ANALYTICAL;
 METHODS: NUMERICAL;
 SHOCK WAVES