Dr. Yuri E. Lyubarsky (Physics Department, Ben-Gurion University, Beer-Sheva, Israel): "Magnetohydrodynamics of pulsar winds and plerions"

Young, rapidly rotating pulsars are surrounded by compact synchrotron nebulae, the Crab Nebula being the best studied and most known example. These nebulae are continuously pumped by electron-positron plasma and magnetic field emanating from the pulsar in the form of relativistic, magnetized wind. High-resolution images in X-ray and optical bands revealed a peculiar "jet-torus" structure in the inner parts of these nebulae. This discovery clearly indicates significant anisotropy of the pulsar wind, which has been ignored so far in simplified theoretical models of the nebula. The recent observations of the Crab also suggest that, contrary to what has been assumed earlier, that the radio emitting electrons are accelerated now in the same region as the ones responsible for the optical to X-ray emission. All these findings provide important clues about the general physical processes such as self-collimation and energy dissipation in high-velocity, magnetized outflows. I discuss the MHD flow and energy transformation processes both in the pulsar wind and in the surrounding nebula. The aim of my talk is to demonstrate that one can account for the new observational results with standard assumptions about the pulsar wind.