Emission of Magnetar Bursts and Precursors of Neutron Star Mergers

Magnetar bursts can be emitted by Alfvén waves growing in the outer magnetosphere to nonlinear amplitudes, ?B/ B ? 1, and triggering magnetic reconnection. Similar flares should occur quasi-periodically a magnetized neutron star binary nearing merger. In both cases, fast dissipation flare creates optically thick e± plasma, whose heat capacity is negligible compared with generated radiation energy. Magnetic then involves photon viscosity acts through Compton drag on plasma bulk motions reconnection region. The effective temperature of resulting Comptonization process self-regulated tens keV. X-ray emission calculated using time-dependent radiative transfer simulations, which follow creation pairs production, Comptonization, escape photons. simulations show how region becomes dressed an coat escaping spectrum shaped coat. results are observed magnetar bursts, including recent activity SGR 1935+2154 accompanied radio burst. Predictions made for precursors mergers.