Gamma-ray bursts are fascinating events, their origin has long been mysterious. Discovered fortuitously in the early 1970s, two categories of gamma-ray bursts could be established depending on the type of progenitor: long bursts (lasting more than two seconds) would be caused by the collapse of massive stars, while for short bursts would come from the coalescence of compact objects. Whatever the progenitor, the mechanisms of emission of the startle remain the same: following the formation of the new compact object, an ejecta in the form of an ultra-relativistic jet probably strongly magnetized is emitted then becomes transparent to its own long-range radiation and by internal dissipation processes, produces prompt emission. The residual emission is due to the braking of this jet in the surrounding environment.
