La mission SVOM et l'étude des sursauts gamma

The SVOM mission and the study of gamma-ray bursts

Frédéric Daigne, Paris Astrophysics Institute, Sorbonne University.

Gamma-ray bursts are the brightest light phenomena known in the universe. They consist of an initial phase of very brief, highly variable and very intense emission in the gamma-ray range, followed by an afterglow observed at all wavelengths. They are produced by jets of matter at very close to the speed of light, ejected by a very compact source (stellar black hole or magnetar) formed following the collapse of a massive star or the coalescence of two neutron stars. These extreme phenomena are of great interest for several reasons: the physics involved (compact objects, relativistic jets, particle acceleration), the link with the evolution of massive stars, and the multi-messenger emission expected from some of them (gravitational waves and neutrinos). Finally, their extreme luminosity means that they can be detected at very great distances and used to study the distant universe. I will present these extreme phenomena and the initial results of the SVOM mission launched in June 2024 to study them.