Speaker
Description
Recent observations of several Gamma-Ray Burst (GRB) afterglows in the TeV domain have profoundly impacted the theory of particle acceleration and radiation in relativistic shocks. We can now confidently state that the Synchrotron-Self-Compton (SSC) model for afterglow emission has successfully passed experimental verification. Furthermore, simultaneous multi-wavelength observations -- spanning from soft X-rays to TeV gamma-rays -- place strict constraints on the emission zone parameters and their temporal evolution. These constraints align with the predictions of the pair-balance model (based on the converter acceleration mechanism) while disfavoring conventional diffusive shock acceleration. Finally, unique observations of the very early TeV afterglow of GRB 221009A provide new insights into the dynamics of the external shock powering the emission. We highlight a hydrodynamic model of a blast wave with intermittent energy supply -- an extension of the standard Blandford-McKee model -- which shows good agreement with the observed light curve.