出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：I have developed 2- and 3-dimensional general relativistic magnetohydrodynamic (GRMHD) code. I performed numerical simulations of collapsars using these codes and realistic progenitor models. In the GRMHD simulation, it was shown that a jet is launched from the central region of the progenitor as long as the central black hole is rotating rapidly. I performed simulations of collapsars with different Kerr parameters a= 0, 0.5, 0.9, 0.95. It is shown that a more rapidly rotating black hole is driving a more energetic jet. No jet is seen for the case of Schwartzschild black hole case, while the total energy of the jet is as large as 1050 erg for a rapidly rotating Kerr black hole case (a=0.95). In order to explain the high luminosity of a GRB, it is concluded that a rapidly rotating black hole is favored ('faster is better'). I also started to perform 3-dimensional GRMHD simulation of collapsars.
