Particle streaming - Is the Alfven velocity the ultimate speed limit

Abstract

view Abstract Citations (96) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Particle streaming: is the Alfvén velocity the ultimate speed limit? Holman, G. D. ; Ionson, J. A. ; Scott, J. S. Abstract It is shown that, because of the resonant damping of waves by thermal protons, nonthermal particles in a hot plasma can in fact stream at a speed which is of the order of or greater than the ion sound speed in the background plasma. This result is in contradiction with previous results which had indicated that in all cases the particle streaming speed is limited to the Alfven velocity due to particle scattering by self-generated hydromagnetic waves. In particular, the propagation of relativistic electrons in the Coma cluster of galaxies and within the supernova remnant Cas A is considered. The results also have implications for the viability of some recently discovered cosmic-ray acceleration mechanisms. Finally, observational studies indicate that a significant fraction of interstellar space is occupied by a hot (T = 1 million K) tenuous gas. If this is so, the considerations discussed here lead to a solution to the often discussed problem of cosmic-ray escape from supernova remnants. Publication: The Astrophysical Journal Pub Date: March 1979 DOI: 10.1086/156881 Bibcode: 1979ApJ...228..576H Keywords: Cosmic Rays; Magnetohydrodynamic Waves; Particle Acceleration; Plasma-Particle Interactions; Propagation Velocity; Relativistic Particles; Galactic Clusters; High Energy Electrons; Interstellar Matter; Ion Acoustic Waves; Plasma Clouds; Supernova Remnants; Astrophysics; Cosmic Rays:Magnetohydrodynamics; Interstellar Plasma; Magnetohydrodynamics:Plasma full text sources ADS |