Résumé / Abstract Journal-club_Hautes_Energies

Journal-club Hautes Energies

« Radiation mediated shocks in gamma-ray bursts »

Filip Samuelsson
Physics Departement, KTH Royal Institute of Technology (Stockholm, Suède)

Shocks that occur below the photosphere in a gamma-ray burst (GRB) jet are mediated by radiation. The roles of such radiation-mediated shocks (RMSs) in the GRB prompt emission have been thoroughly investigated theoretically. However, so far, no such model has been fitted to data due to the computational complexity of simulating RMSs from first principles. We aim to bridge this gap between theory and observation. In this talk, I will present an approximate model called the Kompaneets RMS approximation (KRA) that we have developed for this purpose. With this approximation we can accurately replicate spectra generated by a full-scale RMS simulation using a fraction of the computing time. This allows us to probe a large enough parameter space to fit the model to data, and we illustrate the capabilities of the KRA by performing a fit to a non-thermal spectrum in GRB 150314. With the KRA, we can deduce properties of the original RMS, which allow us to get a better understanding of the dynamics below the photosphere.
jeudi 20 janvier 2022 - 14:00
Webinaire, Institut d'Astrophysique
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