Super-Alfvenic particle streaming in astrophysical settings
Abstract
We discuss the pitch angle scattering of relativistic particles by self-generated hydromagnetic waves. We show that in a hot background plasma, because of the resonant damping of short wavelength waves by thermal protons, cosmic rays need not slow down to a mean streaming speed which is of order the Alfven speed. We also discuss the effects of a high cosmic ray energy density upon the destabilized wave mode. Our recent work indicates that when the cosmic ray energy density is on the order of or exceeds the energy density in the ambient magnetic field, the velocity of the amplified waves is significantly greater than the Alfven speed. These effects have important implications for recent cosmic ray acceleration models and are important for studies of particle propagation in many astrophysical plasmas.
- Publication:
-
Particle Acceleration Mechanisms in Astrophysics
- Pub Date:
- November 1979
- DOI:
- 10.1063/1.32091
- Bibcode:
- 1979AIPC...56..329H
- Keywords:
-
- Cosmic Rays;
- Magnetohydrodynamic Waves;
- Particle Acceleration;
- Plasma-Particle Interactions;
- Relativistic Particles;
- Flow Velocity;
- High Temperature Plasmas;
- Magnetohydrodynamic Turbulence;
- Pitch (Inclination);
- Space Radiation;
- 95.30.Qd;
- Magnetohydrodynamics and plasmas