The Smoking Guns Of Neutron Stars Mergers

The short hard gamma ray burst (SHB) 170817A that followed the first neutron stars merger (NSM) detected in gravitational waves (GWs) has shown beyond doubt that NSMs produce SHBs. Its low luminosity and other properties that differ from those of ordinary SHBs, were predicted by the cannonball model of GRBs for relatively nearby SHBs, which almost entirely are low luminosity SHBs viewed from far off-axis. Such far off-axis low luminosity SHBs are mostly the smoking guns of only nearby NSMs, like those detectable by Ligo-Virgo. The smoking guns of much more distant NSMs are PWN afterglows powered by the spin-down of the nascent n*s, preceded by a visible SHB, or by an invisible SHB, which is beamed away from Earth.