Magnetic reconnection at the termination shock in a striped pulsar wind Yuri Lyubarsky Ben-Gurion University, Israel In collaboration with: Jerome Petri (now at Strasbourg Obs) Michael Liverts (BGU)

How the Poynting flux is transferred to radiating particles in the nebula? The answer (general): most of the energy is transferred by the waves; the waves decay. Analytical model (Bogovalov 1999) Numerical solution (Spitkovsky 2005)

The questions under discussion: where and how the waves decay? The main goals of this talk: 1. Find criterion for the dissipation of the waves at the at the pulsar wind termination shock. 2. Demonstrate that in PWNe, the waves decay at the terminations shock unless they decayed in the wind. 3. Apply the obtained criterion to the bow shocks in binary pulsar systems. 4. Discuss the observational signatures of the wave decay at the shock front.

jj   Shock in a striped wind

negligible dissipationpartial dissipationcomplete dissipation jj   l1l1 l2

The shock in a striped wind, 1.5D PIC simulations

Condition for complete dissipation: analytical numerical

Alternating fields dissipate at the termination shock provided the shock occurs at the distance In PWNe R/R L ~10 9 >>  therefore even if the waves do not dissipate in the wind they do at the termination shock.

Binary pulsars secondary shock pulsar wind

Double pulsar PSR J Modulation of the radio emission from B with the period of A: alternating fields in the wind from A are not erased completely. PSR and PSR : X-ray emission from the shocked plasma implies efficient dissipation of the Poynting flux.

Enigma of the radio emitting electrons in plerions The acceleration process should somehow transfer most of the total energy of the system to a handful of particles leaving for the majority only a small fraction of the energy

Particle acceleration by forced annihilation of alternating magnetic fields

2.5 PIC simulations of the driven reconnection

Evolution of the particle spectrum

Romanova & Lovelace 1992; Larrabee, Lovelace & Romanova 2002

Conclusions 1. In relativistic, Poynting dominated flows, alternating magnetic fields are dissipated at the shock front provided Under this condition, the downstream parameters are determined by the total energy flux and the mean magnetic field 2. The condition for full magnetic dissipation is satisfied at the termination shock in the PWNe. In binary pulsars, the condition for full dissipation imposes constraints on the pair multiplicity in the pulsar wind 3. Particles are accelerated in the course of the driven reconnection;