Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2009-02-11
Astrophys.J.704:937-950,2009
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
14 pages, 17 figures, Submitted to The Astrophysical Journal, High resolution version is available at http://www2.yukawa.kyo
Scientific paper
10.1088/0004-637X/704/2/937
In order to investigate formation of relativistic jets at the center of a progenitor of a long gamma-ray burst (GRB), we develop a two-dimensional general relativistic magnetohydrodynamic (GRMHD) code. We show the code passes many, well-known test calculations, by which the reliability of the code is confirmed. Then we perform a numerical simulation of a collapsar using a realistic progenitor model. It is shown that a jet is launched from the center of the progenitor. We also find that the mass accretion rate after the launch of the jet shows rapid time variability that resembles to a typical time profile of a GRB. The structure of the jet is similar to the previous study: a poynting flux jet is surrounded by a funnel-wall jet. Even at the final stage of the simulation, bulk Lorentz factor of the jet is still low, and total energy of the jet is still as small as 10^48 erg. However, we find that the energy flux per unit rest-mass flux is as high as 10^2 at the bottom of the jet. Thus we conclude that the bulk Lorentz factor of the jet can be potentially high when it propagates outward. It is shown that the outgoing poynting flux exists at the horizon around the polar region, which proves that the Blandford-Znajek mechanism is working. However, we conclude that the jet is launched mainly by the magnetic field amplified by the gravitational collapse and differential rotation around the black hole, rather than the Blandford-Znajek mechanism.
No associations
LandOfFree
Development of General Relativistic Magnetohydrodynamic Code and its Application to Central Engine of Long Gamma-Ray Bursts does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Development of General Relativistic Magnetohydrodynamic Code and its Application to Central Engine of Long Gamma-Ray Bursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Development of General Relativistic Magnetohydrodynamic Code and its Application to Central Engine of Long Gamma-Ray Bursts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-488168