主要内容:
数值模拟盘的形成。还提到了伽马暴喷流的形成。
精彩摘抄:
文章信息:
- · arXiv e-print (arXiv:1009.5303)
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| Title: |
| Formation of black hole and accretion disk in collapsar |
| Authors: |
| Sekiguchi, Yuichiro; Shibata, Masaru |
| Publication: |
| eprint arXiv:1009.5303 |
| Publication Date: |
| 09/2010 |
| Origin: |
| ARXIV |
| Keywords: |
| Astrophysics - High Energy Astrophysical Phenomena |
| Comment: |
| 28 pages, 26 figures with low resolution, abstract is shortened, submitted to ApJ |
| Bibliographic Code: |
| 2010arXiv1009.5303S |
Abstract
We present the first numerical result of full-GR simulations for the collapse of a rotating high-entropy stellar core to a BH and accretion disk. The simulations are performed taking into account the relevant microphysics such as nuclear-theory-based finite-temperature EOS, weak interaction processes, and neutrino cooling in a general relativistic leakage scheme. The initial core is modeled by a spherical configuration with a constant $Y_e = 0.5$ and s = 8 $k_B$, with rotational profiles added. In all models, collapse to a BH proceeds as follows: In the early phase, the core collapses and then experiences a gas-pressure-dominated bounce. Because the bounce is too weak to halt the collapse, a BH with the initial mass of $\sim 6$--$7M_{\odot}$ is eventually formed. Subsequent evolution depends sensitively on the amount of rotation. For the case that the rotation is not fast, a geometrically thin accretion disk is formed around the BH, and a standing shock wave is formed in the inner part of the disk. For the moderately rotating case, the thin disk expands eventually to be a geometrically thick torus after sufficient accumulation of the thermal energy generated at the shocks, and then, convection occurs inside the torus, because a region with negative entropy gradient emerges due to the interplay of the shock heating, neutrino cooling, and the neutrino trapping. In the long-term evolution of the torus, neutrino luminosities vary violently with time because of the convective motion. For the rapidly rotating case, by contrast, a geometrically thick torus is immediately formed soon after the BH formation. Based on our results, we describe a scenario for the generation of relativistic jets of long gamma-ray bursts in the collapse of a population III star. We also estimate GW due to anisotropic emission of neutrinos, and find that it may have a larger amplitude than previously estimated.
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