伽玛暴(Gamma-Ray Burst)笔记。记录有关伽玛暴的新文章,另外也包括看的老文章、自己的想法、以及跟天文相关的一些东西。 Feel free to leave me a message by comments or by email.

星期四, 十月 28, 2010

Nagataki 2010 旋转的黑洞作为中心引擎,越快越好

主要内容:


精彩摘抄:


文章信息:


· Find Similar Abstracts (with default settings below)
· arXiv e-print (arXiv:1010.4964)
· References in the Article
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Rotating BHs as Central Engines of Long GRBs: Faster is Better
Authors:
Nagataki, Shigehiro
Publication:
eprint arXiv:1010.4964
Publication Date:
10/2010
Origin:
ARXIV
Keywords:
Astrophysics - High Energy Astrophysical Phenomena
Comment:
8 pages, 7 figures, Publications of the Astronomical Society of Japan (PASJ), submitted
Bibliographic Code:
2010arXiv1010.4964N

Abstract

We 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 10^{50} 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'). We also find in the case of a=0.95 that (i) the stagnation region is clearly found in the jet region, (ii) the ordered poloidal field lines are seen in the jet, (iii) the jet region is surrounded by a 'Wall-like' structure that has a higher pressure than the jet region and contains strong vertical magnetic fields, and (iv) the jet is initiated by outgoing Poynting flux from the outer horizon of the black hole (Blandford-Znajek effect). The bulk Lorentz factor of the jet is still of the order of unity. However, energy density of electro-magnetic fields dominates the one of rest-mass in the jet. It can be expected that a relativistic jet will be seen if we perform a simulation for a longer time scale (of the order of 10-100 sec).
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

没有评论: