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arXiv 0709.0381astro-ph
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伽马射线暴率出乎意料地迅速上升

An Unexpectedly Swift Rise in the Gamma-ray Burst Rate

Matthew D. Kistler, Hasan Yuksel, John F. Beacom, Krzysztof Z. Stanek

摘要:

长伽马射线暴与超新星的关联自然表明,宇宙伽玛射线暴率应该跟踪恒星形成的历史。如果发现其他情况,将为这些罕见的奇怪现象提供重要线索。使用一个新的估计雨燕伽玛暴能量构建一个样本的36个明亮的伽玛暴的红移范围在z=0-4,我们发现的证据增强的伽玛暴速率的演化,与4倍的伽玛暴观测到的z~4比预期的恒星形成测量。这种对所需的额外进化的直接和经验性的证明是一个新的结果。这与金属丰度效应的理论预期是一致的,但其他原因仍然是可能的,我们系统地考虑它们。

英文摘要:

The association of long gamma-ray bursts with supernovae naturally suggests that the cosmic GRB rate should trace the star formation history. Finding otherwise would provide important clues concerning these rare, curious phenomena. Using a new estimate of Swift GRB energetics to construct a sample of 36 luminous GRBs with redshifts in the range z=0-4, we find evidence of enhanced evolution in the GRB rate, with ~4 times as many GRBs observed at z~4 than expected from star formation measurements. This direct and empirical demonstration of needed additional evolution is a new result. It is consistent with theoretical expectations from metallicity effects, but other causes remain possible, and we consider them systematically.

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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