Le 21 mars 2014
J.G. Kirk
Max-Planck-Institut für Kernphysik, Heidelberg, Germany
Pulsar winds are made up of low density, magnetized, relativistic plasmas. When they impact the interstellar medium, they form a shock front which accelerates the particles responsible for Pulsar Wind Nebulae – the dominant galactic sources of very high energy gamma-rays. However, if the shock obeys the standard MHD jump conditions in a strongly magnetized plasma, it is not effective at dissipating the wind energy into particles. A way out of this problem is possible if the magnetic field arrving at the termination shock fluctuates on the rotation timescale of the pulsar, as expected in the « striped wind » model. In this case, dissipation is possible either by driven reconnection in the compressed downstream plasma, or by conversion of the fluctuations into damped superluminal electromagnetic modes. In this talk, I will briefly describe the basic ideas behind pulsar wind theory, before discussing recent work on the role played by electromagnetic waves, and their possible radiative signatures.