Superluminal signals from gamma ray bursts

by Arnon DAR (Technion)

Thursday 21 Sept 2000, 14:00 → 14:15 Europe/Zurich

TH Auditorium (CERN)

We propose that falling back material in supernova explosions produces, within a day, a transient accretion disk around the central compact object. The accretion generates highly relativistic jets as in the observed ejection of highly relativistic ``cannonballs'' of plasma by microquasars and active galactic nuclei. The collision of the jetted cannonballs with the SN shell produces a collimated sub-TeV neutrino burst. As the jetted cannonballs exit the supernova shell reheated by the collision, their own radiation and the scattered light of the shell are Lorentz boosted to gamma ray energies and are collimated along their motion into a gamma ray burst (GRB). The jetted cannonballs decelerate by sweeping up interstellar matter, which is accelerated to cosmic-ray energies and emits synchrotron radiation: the afterglow. Observational evidence for the gamma ray burst - supernova association will be presented. A smoking-gun signature of this model of GRBs: the superluminal motion of the afterglow, which should be still observable in the nearest known GRB, GRB980425/SN1998bw with the Hubble Space Telescope and with Very Large Arrays/Very Large Base Interferometers, will be discussed.