Hydrodynamical constraints on cosmic-ray acceleration in relativistic shocks

Journal Article · Sat Aug 01 00:00:00 EDT 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165448· OSTI ID:5931691

Webb, G M

A two-fluid hydrodynamical model governing the transport of cosmic rays in a relativistically moving background plasma is developed. The equations are used to discuss the time asymptotic structure of a relativistic, plane-parallel shock wave significantly modified by first-order Fermi acceleration of cosmic rays. The model allows for an anisotropic cosmic-ray pressure tensor with pressure components parallel and perpendicular to the shock normal. It is surmised that the well-known energy threshold problem for diffusive shock acceleration that downstream particles have a large enough velocity to overtake the shock and subsequently scatter in the upstream medium before returning to the downstream medium may be expressed hydrodynamically by the condition V less than V(cr), where V is the fluid velocity relative to the shock and V(cr) is the relativistic cosmic-ray sound speed. Astrophysical implications of the results are briefly discussed. 65 references.

• Research Organization: Arizona Univ., Tucson
• OSTI ID: 5931691
• Journal Information: Astrophys. J.; (United States), Vol. 319
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC RADIATION
ACCELERATION
ANISOTROPY
CONSTRAINTS
HYDRODYNAMIC MODEL
RADIATION PRESSURE
RELATIVISTIC PLASMA
SHOCK WAVES
TWO-PHASE FLOW
WAVE PROPAGATION
FLUID FLOW
IONIZING RADIATIONS
MATHEMATICAL MODELS
PARTICLE MODELS
PLASMA
RADIATIONS
STATISTICAL MODELS
THERMODYNAMIC MODEL
640101* - Astrophysics & Cosmology- Cosmic Radiation