SupraNova Events from Spun-up Neutron Stars: an Explosion in Search of an Observation

Abstract

We consider a formation scenario for supramassive neutron stars (SMNSs) taking place through mass and angular momentum transfer from a close companion during a Low Mass X-ray Binary (LMXB) phase, with the ensuing suppression of the magnetic field. We show that this formation channel is likely to work for all equations of state except the stiffest ones. After the end of the mass transfer phase, SMNSs will loose through magnetic dipole radiation most of their angular momentum, triggering the star's collapse to a black hole. We discuss the rate of occurrence of these collapses, and propose that these stars, because of the baryon-clear environment in which the implosion/explosion takes place, are the originators of gamma ray bursts.