BGU Physics Department

Colloquium, Dec. 27th, 2012

Gamma-Ray Bursts: the Quest for the Progenitors

Elena Pian,  INAF, Trieste Astronomical Observatory, Trieste, Italy and  Scuola Normale Superiore,  Pisa, Italy

Ever since the multi-wavelength counterparts of Gamma-Ray Bursts (GRBs) have been detected, more than 15 years ago, new mysteries and unknowns have taken the place of old questions and the field has become a laboratory for a vast range of astrophysical topics, primarily stellar evolution and explosions. Identifying GRB progenitors and their evolutionary paths is one of the biggest outstanding problems about these sources.  While the properties of short-duration GRBs and their host galaxies suggest compact binary star mergers as potential progenitors (but no direct observation has proved it), long duration GRBs are unambiguously associated with  stripped-envelope core-collapse supernovae.  These are a subset of so-called Type Ic supernovae with very high kinetic energies, but the mechanism by which such powerful supernovae produce relativistic jets is not clear.  I will review the state-of-the-art of the observations and the fundamental problems that are still currently open.