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arXiv 1109.3757astro-ph.HE
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GRBS的洛伦兹因子-各向同性光度/能量关联及其解释

Lorentz Factor-Isotropic Luminosity/Energy Correlations of GRBS and Their Interpretation

Jing Lv, Yuan-Chuan Zou, Wei-Hua Lei, Bing Zhang, Qing-Wen Wu, Ding-Xiong Wang, En-Wei Liang, Hou-Jun Lv

摘要:

伽马射线暴(GRB)喷出物(γ_0)的体洛伦兹因子是理解GRB物理的一个关键参数。Liang等人发现了γ_0和各向同性γ射线能量之间的相关性:γ_0 \proptoE_{gamma,iso,52}^{0.25}。通过包括更多的具有更新数据的伽玛暴和更多的方法来获得γ_0,我们证实了这种相关性,并获得了γ_0 ~91 E_{gamma,iso,52} ^{0.29}。对同一样品中各向同性伽玛暴的平均亮度L_{gamma,iso}进行了计算,发现它们之间有更紧密的相关性:γ_0 ~249 L_{gamma,iso,52} ^{0.30}。我们提出了一个解释,后来的相关性。我们假设恒星质量黑洞周围的中微子冷却超吸积盘是伽玛暴的中心发动机,从中微子驱动的风中导出了中微子湮灭和重子加载驱动的喷流光度。应用聚束校正,我们最终得到了与实验数据符合较好的伽玛0 \proptoL_{gamma,iso}^{0.22}。这表明长伽玛暴的中心引擎很可能是一个被超吸积盘包围的恒星质量的黑洞。

英文摘要:

The bulk Lorentz factor of the gamma-ray burst (GRB) ejecta (Gamma_0) is a key parameter to understand the GRB physics. Liang et al. have discovered a correlation between Gamma_0 and isotropic gamma-ray energy: Gamma_0\proptoE_{gamma,iso,52}^{0.25}. By including more GRBs with updated data and more methods to derive Gamma_0, we confirm this correlation and obtain Gamma_0~91E_{gamma,iso,52}^{0.29}. Evaluating the mean isotropic gamma-ray luminosities L_{gamma,iso} of the GRBs in the same sample, we discover an even tighter correlation Gamma_0~249 L_{gamma,iso,52}^{0.30}. We propose an interpretation to this later correlation. Invoking a neutrino-cooled hyperaccretion disk around a stellar mass black hole as the central engine of GRBs, we derive jet luminosity powered by neutrino annihilation and baryon loading from a neutrino-driven wind. Applying beaming correction, we finally derive Gamma_0\proptoL_{gamma,iso}^{0.22}, which is well consistent with the data. This suggests that the central engine of long GRBs is likely a stellar mass black hole surrounded by a hyper-accreting disk.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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