Can Neutrino-cooled Accretion Disks Be an Origin of Gamma-Ray Bursts?
Can Neutrino-cooled Accretion Disks Be an Origin of Gamma-Ray Bursts?
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DOI：
10.1086/342166
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发表时间：
2002-03
期刊：
影响因子：
--
通讯作者：
K. Kohri;S. Mineshige
中科院分区：
文献类型：
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作者：
K. Kohri;S. Mineshige
人们经常提出，围绕恒星质量黑洞的一个大约太阳质量的巨大环面可能是伽马射线爆发的中心引擎。我们基于α粘滞模型研究了这种大质量吸积环（或盘）的性质。当面密度超过1020 g cm-2时，我们发现：（1）由于大量的光子俘获，光子的光度几乎为零;（2）中微子冷却超过平流冷却;（3）简并电子的压力超过气体和光子的压力，（4）磁场强度超过临界值4 × 10 ~（13）G，即使取均分值的0.1%。讨论了超临界场可能产生的量子电动力学（QED）效应。最有趣的是，可能会发生光子分裂，产生大量能量低于~511 keV的光子，从而可能抑制e±对的产生。
It is often proposed that a massive torus with approximately solar mass surrounding a stellar-mass black hole could be a central engine of gamma-ray bursts. We study the properties of such massive accretion tori (or disks) based on the α viscosity model. For surface density exceeding about 1020 g cm-2, which is realized when ~1 M☉ of material is contained within a disk of size ~5 × 106 cm, we find that (1) the luminosity of photons is practically zero because of significant photon trapping, (2) neutrino cooling dominates over advective cooling, (3) the pressure of degenerate electrons dominates over the pressure of gas and photons, and (4) the magnetic field strength exceeds the critical value of about 4 × 1013 G, even if we take 0.1% of the equipartition value. The possible observable quantum electrodynamical (QED) effects arising from supercritical fields are discussed. Most interestingly, photon splitting may occur, producing a significant number of photons of energies below ~511 keV, thereby possibly suppressing e± pair creation.