On GRB Physics Revealed by FERMI/LAT
Abstract
We discuss the implications of Fermi/LAT observations on several aspects of gamma-ray burst (GRB) physics, including the radiation process, the emission sites, the bulk Lorentz factor, and the pre-shock magnetic field: (1) MeV-range emission favors synchrotron process but the highest energy (>10GeV) emission may not be synchrotron origin, more likely inverse Compton origin; (2) GRB should have multi-zone emission region, with MeV emission produced at smaller radii while optical and >100MeV emission at larger radii; (3) the bulk Lorentz factor can be a few 100's, much lower than 10^3, in multi-zone model; (4) the upstream magnetic field of afterglow shock is strongly amplified to be at least in mG scale.
Cite
@article{arxiv.1201.0262,
title = {On GRB Physics Revealed by FERMI/LAT},
author = {Zhuo Li},
journal= {arXiv preprint arXiv:1201.0262},
year = {2012}
}
Comments
5 pages; invited, to appear in the proceedings of the 3rd Galileo-XuGuangQi meeting, October 11-15, 2011, Beijing, China