The Role of Magnetic Fields in Gamma-Ray Bursts from SNeII

Abstract

Data from a recently discovered long Gamma Ray Burst (GRB 090102) by NASA ’ s Swift satellite revealed that such GRBs may not be fireballs as usually presumed, but instead they are powered and collimated by organized strong magnetic fields ( ≧ 10 15 G ) generated by the compact object, a neutron star (NS) created at the core of the associated supernova explosion (SNeII). A mechanism for the generation of such strong surface magnetic fields where power NSs result from the deaths of massive progenitor stars is described based on a non-conventional model for pulsar magnetic fields, namely, spinning polarization charge that I recently developed in [1]. I show that this could give rise to scenarios involving long GRB events as the one captured by the Swift satellite during GRB 090102 in January 2, 2009. The model predicts that the magnetic moment of a NS has a dynamical feature which makes it different from that of a simple pulsar. I show this could have serious consequences on the statistics of observing long GRBs and also help explain such scenarios as the steep decline in the photon count-rate and the subsequent shutoff in the Swift/XRT X-ray data from GRB 070110.