The nature of the extended GeV emission in GRBs (invited)

Author: Nicola Omodei

Abstract: The Fermi Large Area Telescope is providing new and exciting information on the nature of the temporally extended high-energy emission observed in some Gamma-ray Bursts.

In this talk I will review the observational characteristics of this long lasting emission, such as its delayed onset with respect the low energy prompt emission, the presence of an additional spectral component, and the detections of breaks in its temporal decay.

I will put these observations in the context of the current theoretical understanding, discussing the relationship between the extended GeV emission and the prompt emission in Gamma-Ray Bursts.