The Crab nebula`s ``wisps`` as shocked pulsar wind

Conference · Mon Jul 20 04:00:00 EDT 1992

OSTI ID:10107754

Gallant, Y A; Arons, J ^[1]; Langdon, A B ^[2]

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1. California Univ., Berkeley, CA (United States). Theoretical Astrophysics Center
2. Lawrence Livermore National Lab., CA (United States)

The Crab synchrotron nebula has been successfully modelled as the post-shock region of a relativistic, magnetized wind carrying most of the spindown luminosity from the central pulsar. While the Crab is the best-studied example, most of the highest spindown luminosity pulsars are also surrounded by extended synchrotron nebulae, and several additional supernova remnants with ``plerionic`` morphologies similar to the Crab are known where the central object is not seen. All these objects have nonthermal, power-law spectra attributable to accelerated high-energy particles thought to originate in a Crab-like relativistic pulsar wind. However, proposed models have so far treated the wind shock as an infinitesimally thin discontinuity, with an arbitrarily ascribed particle acceleration efficiency. To make further progress, investigations resolving the shock structure seemed in order. Motivated by these considerations, we have performed ``particle-in-cell (PIC) simulations of perpendicularly magnetized shocks in electron-positron and electron-positron-ion plasmas. The shocks in pure electron-positron plasmas were found to produce only thermal distributions downstream, and are thus poor candidates as particle acceleration sites. When the upstream plasma flow also contained a smaller population of positive ions, however, efficient acceleration of positrons, and to a lesser extent of electrons, was observed in the simulations.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10107754
• Report Number(s): UCRL-JC--111254; CONF-9202117--8; ON: DE93003466; CNN: Grant AST-9115093
• Country of Publication: United States
• Language: English

Related Subjects

661300
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPUTERIZED SIMULATION
CRAB NEBULA
EQUATIONS OF MOTION
OTHER ASPECTS OF PHYSICAL SCIENCE
PULSARS
SHOCK HEATING
SHOCK WAVES
SOLITONS
SYNCHROTRON RADIATION