International School of Cosmic Ray Astrophysics
14th Course: "Neutrinos and Explosive Events in the Universe"
A NATO Advanced Study Institute
2-13 July 2004
Ettore Majorana Centre
Erice, Sicily, Italy
Topic: Hypernovae and Gamma-ray
Lecturer: Konstantin Postnov
Gamma-ray bursts are recognized as strongly relativistic jet outflows occurring roughly once per a million year or per galaxy. A growing observational evidence indicates that long cosmic gamma-ray bursts (whose location can be obtained by follow-up multiwavelength observations) are associated with most energetic stellar explosions, a certain class type Ib/c supernovae, collectively dubbed hypernovae. On the basis of recent multiwavelength studies of GRBs, I will critically review direct and undirect evidence for such an association. The present understanding of gamma-ray emission formation will then be discussed. Next, hot (baryonic) versus cold (Poynting-dominated) jets as the GRB sources will be considered. In conclusion, possible high-energy signatures of GRB explosions will be briefly discussed and future prospects for GRB studies in the Swift and GLAST era will be described.
Recommended recent general reviews on GRB include:
1. K. Hurley, R. Sari, S. G. Djorgovski. Cosmic Gamma-Ray Bursts, Their Afterglows, and Their Host Galaxies. astro-ph/0211620
2. P. Meszaros. Theories of Gamma-Ray Bursts. Ann.Rev.Astron.Astrophys. 40 (2002) 137-169 (astro-ph/0111170).