Relativistic shock waves and the excitation of plerions

Conference · Wed Aug 05 04:00:00 EDT 1992 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:6431124

Arons, J ^[1]

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1. Departments of Astronomy and of Physics, University of California at Berkeley ( ) Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory ( )

The shock termination of a relativistic magnetohydrodynamic wind from a pulsar is the most interesting and viable model for the excitation of the synchrotron sources observed in pulsar driven ( plerionic'') supernova remnants. I describe results on the structure of relativistic magnetosonic shock waves in plasmas composed of electrons and positrons plus heavy ions as a minority constituent by number. Relativistic shocks in symmetric pair plasmas create fully thermalized distributions of particles and fields downstream. Therefore, such shocks are not good candidates for the mechanism which converts rotational energy lost from a pulsar into the nonthermal synchrotron emission observed in plerions. However, when the upstream wind contains heavy ions which are a minority constituent by number density, but carry the bulk of the energy density, much of the energy of the shock goes into a downstream, nonthermal power law distribution of pairs with energy distribution [ital N]([ital E])[ital dE][proportional to][ital E][sup [minus][ital s]]. In a specific model presented in some detail, [ital s]=1.7, with approximately 20% efficiency in converting upstream flow energy into downstream energy in nonthermally accelerated particles. These characteristics are close to those assumed for the pairs in macroscopic MHD wind models of plerion excitation. The acceleration mechanism is collective synchrotron emission of elliptically polarized extraordinary modes by the ions in the shock front at high harmonics of the ion cyclotron frequency, with the downstream pairs absorbing almost all of this radiation, mostly at their fundamental (relativistic) cyclotron frequencies.

• OSTI ID: 6431124
• Report Number(s): CONF-9112103--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 264:1
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340 -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
COSMIC RADIO SOURCES
CRAB NEBULA
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FLUID MECHANICS
HYDRODYNAMICS
LEPTONS
MAGNETOHYDRODYNAMICS
MATTER
MECHANICS
NEBULAE
POSITRONS
PULSARS
RADIATION SOURCES
RELATIVISTIC RANGE
SHOCK WAVES
SUPERNOVA REMNANTS
SYNCHROTRON RADIATION SOURCES