Departament d'Astronomia i Astrofísica
Universitat de València

    Gamma ray bursts central machine as magnetically driven collapsar model

Dr. M.V. Barkov

Department of Applied Mathematics (University of Leeds, UK) Space Research Institute (Moscow, Russia)

Seminari del departament d'Astronomia i AstrofĂ­sca

Dijous 26 juny 2008



In this work we describe the results of our numerical study on the possibility of magnetic origin of relativistic jets of long duration gamma ray bursts 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 solutions for several models where the progenitor star has different magnetic field and for different envelop accretion rates. The some solution exhibits strong explosion driven by the Poynting-dominated jets whose power exceeds up to 12 X 10^51 {erg s}^{-1}. The criterion for explosion were derived. The jets originate mainly from the black hole and they are powered via the Blandford-Znajek mechanism. A number of simulation movies can be downloaded from http://www.maths.leeds.ac.uk/~serguei/research/movies/anim.html