Energy balance in the course of relativistic magnetic reconnection

Abstract

Magnetic reconnection plays an important role in space physics, for example, in Earth's magnetosphere, on the Sun, in the magnetospheres ofmagnetars, pulsars, black holes, etc. Reconnection starts with abrupt drop of plasma conductivity in a small part of a current sheet, so called,diffusion region. As a result electric field is generated and is transferred by relativistic MHD surface wave from the diffusion region to thecurrent sheet which leads to decay of the disturbed part of the current sheet into a system of slow shocks. Plasma is highly accelerated andheated at the shock fronts forming outflow region with relativistic plasma jets and weak magnetic field (Semenov & Bernikov1991). At some stage the reconnection process has to switch-off, then outflow regions must detach from the site where the electricfield was initiated, and propagate along the current sheet as solitary waves (Tolstykh et al. 2005). The energy balance ofrelativistic reconnection is investigated in details. It is shown that magnetic and thermal energy from the inflow region is spent foracceleration and heating of the plasma in jets. It is interesting that the temperature of the plasma in the wake of the propagating outflowregions drops after each pulse of reconnection. This differ from usual explosion which heats the plasma behind the shock front (Tolstykh etal. 2007).