A corrugated termination shock in pulsar wind nebulae?

Abstract

Successful phenomenological models of pulsar wind nebulae assume efficient dissipation of the Poynting flux of the magnetized electron-positron wind as well as efficient acceleration of the pairs in the vicinity of the termination shock, but how this is realized is not yet well understood. The present paper suggests that the corrugation of the termination shock, at the onset of non-linearity, may lead towards the desired phenomenology. Non-linear corrugation of the termination shock would convert a fraction of order unity of the incoming ordered magnetic field into downstream turbulence, slowing down the flow to sub-relativistic velocities. The dissipation of turbulence would further preheat the pair population on short length scales, close to equipartition with the magnetic field, thereby reducing the initial high magnetization to values of order unity. Furthermore, it is speculated that the turbulence generated by the corrugation pattern may sustain a relativistic Fermi process, accelerating particles close to the radiation reaction limit, as observed in the Crab nebula. The required corrugation could be induced by the fast magnetosonic modes of downstream nebular turbulence; but it could also be produced by upstream turbulence, either carried by the wind or seeded in the precursor by the accelerated particles themselves.

arXiv comment17 pages, 1 figure; to appear in J. Plasma Phys

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Cited by in corpus (9)

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• Particle acceleration in relativistic turbulence: A theoretical appraisal
• Non-resonant particle acceleration in strong turbulence: comparison to kinetic and MHD simulations
• A global model of particle acceleration at pulsar wind termination shocks
• Nonlinear aspects of stochastic particle acceleration
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