The origin of the prompt emission in gamma-ray bursts (GRBs) remains highly debated despite decades of research. The GRB jet is initially optically thick and the trapped radiation is released when the jet transitions to the optically thin regime at the photospheric radius. Due to the high radiation pressure close to the central engine, shocks that occur before this transition are radiation mediated. In this seminar, I give an introduction to the theory of radiation-mediated shocks (RMSs) in the context of GRBs. I show that such shocks are expected in GRB jets and that the energized radiation downstream of the shock exhibits several promising features with regard to the observations. However, these shocks are computationally challenging to model from first principles. With this motivation, we have developed an approximate simulation code that is both quick and accurate. The simulation code is unique in its ability to fit an RMS model to the observational data.
Local contact & organisation: Thierry FOGLIZZO
DAp