Gamma-ray bursts (GRBs) are sudden and intense bursts of X- and gamma-ray light. They are linked to the cataclysmic formation of black holes, either by the merger of two compact stars (neutron stars or black holes), or by the sudden explosion of a massive star, 20 to 100 times larger than our Sun. The birth of a black hole comes with the formation of material jets travelling at nearly the speed of light (300,000 km per second). These material jets then slow down in the circumstellar medium, sweeping up everything in their way. Bright GRBs can be observed in the confines of the Universe, acting as real beacons lighting the dark age of its creation.
Despite continuing research effort over the last 15 years, GRBs are still poorly understood.