Stellar explosions powered by the Blandford-Znajek mechanism

TL;DR

This study uses numerical simulations to demonstrate that magnetic fields and the Blandford-Znajek mechanism can power relativistic jets in gamma-ray burst scenarios from collapsing massive stars, showing strong jet-driven explosions.

Contribution

First numerical demonstration of jet formation via the Blandford-Znajek mechanism in collapsar gamma-ray burst models using realistic physics.

Findings

Jets driven mainly from the black hole with power > 2×10^51 erg/s

Jets are Poynting-dominated and originate from the black hole

Simulation results support magnetic origin of relativistic jets in collapsars

Abstract

In this letter we briefly describe the first results of our numerical study on the possibility of magnetic origin of relativistic jets of long duration gamma ray bursters within the collapsar scenario. We track the collapse of massive rotating stars onto a rotating central black hole using axisymmetric general relativistic magnetohydrodynamic code that utilizes a realistic equation of state of stellar matter, takes into account the cooling associated with emission of neutrinos, and the energy losses due to dissociation of nuclei. The neutrino heating is not included. We describe the solution for one particular model where the progenitor star has magnetic field $B=10^{10}$G. The solution exhibits strong explosion driven by the Poynting-dominated jets whose power exceeds $2\times10^{51} {erg/s}$. The jets originate mainly from the black hole and they are powered via the Blandford-Znajek mechanism. The full details of the simulations together with the results of parameter study will be presented elsewhere. A number of simulation movies can be downloaded from http://www.maths.leeds.ac.uk/~serguei/research/movies/anim.html