On the mechanism of prompt emission of gamma-ray bursts

We propose a model in which prompt gamma emission of gamma-ray bursts is the synchrotron radiation of electron-positron plasma in the ordered magnetic field in the direct vicinity of horizon of a young black hole formed in the core collapse of a massive star. This mechanism can naturally explain high degree of polarization of the gamma-ray flux and hard low energy photon spectral index. Interaction of gamma-quanta with ambient matter provides a mechanism of formation of relativistic ejecta which are responsible for the gamma-ray burst afterglows.