Cannonball model diagnosis of the short gamma ray burst 170817A

TYPEAstrophysics Seminar
Speaker:Arnon Dar
Time:14:30 - 15:30
Location:Lidow 620
Remark:Based on: Shlomo Dado, Arnon Dar, "The Smoking Guns Of Short Hard Gamma Ray Bursts", arXiv:1708.04603

Thirty years ago Goodman, Dar and Nussinov suggested that neutron star mergers (NSMs) due to gravitational wave emission may produce gamma ray bursts (GRBs). On August 15, 2017, two days before the first detection of NSM in gravitational waves (GWs) followed by a short hard gamma ray burst (SHB) 2 second later, Dado and Dar posted a paper in the arXiv* claiming that GW detections of NSMs by Ligo-Virgo, will be followed only by a far off-axis SHB or by an orphan afterglow. After the ground breaking discovery of GW170817-SHB170817 on August 17, 2017 and the follow up measurements of the afterglow of SHB170817 we have confronted the detailed predictions of the cannonball model of GRBs with the rich and complex data obtained from the multi-wavelength observations of SHB170817A. I will show that they are well predicted/explained/reproduced by the cannonball model of SHBs.  In this model a highly relativistic jet was launched in the NSM into a light fireball, produced days before the nascence of a massive neutron star or black-hole remnant.  The SHB was produced by inverse Compton scattering of fireball photons by the jet, which was viewed far off-axis. The thermal radiation from the fading fireball produced the initial UVOIR afterglow, whose bolometric light curve favors a neutron star over a black-hole as the compact remnant of NSM170817. Its late time X-ray UVOIR and radio afterglow was produced by synchrotron radiation from the jet. If the radio afterglow of SHB170817A was indeed produced by the jet, it should display a superluminal motion relative to the SHB location, still detectable in VLA and VLBI radio observations.