Short gamma-ray bursts as a possible probe of binary neutron star mergers
Short gamma-ray bursts as a possible probe of binary neutron star mergers
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DOI：
10.1088/1475-7516/2004/06/007
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发表时间：
2004-05
影响因子：
6.4
通讯作者：
S. Ando
中科院分区：
文献类型：
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作者：
S. Ando
我们研究了短伽玛射线暴的性质，假设它们都与双星中子星星合并有关，其机制包含大量的不确定性。特别是，合并的时间分布，这是必不可少的短伽玛暴率估计，是重点;我们参数化它简单地为Pm（t）<$tα与较低的截止时标τ。用这种参数化方法和宇宙星星形成率的一个特定模型计算得到的短γ暴率对τ值很不敏感，但对α值很敏感。使用此类形成率模型，可以拟合由BatSE观察到的峰值通量分布。在拟合过程中，局部短伽玛暴率ρ0被视为自由参数之一，当ρ0 = 0.1-2 yr−1 Gpc−3时，拟合效果最好，这取决于其他自由参数以及由（τ，α）表示的形成率模型。我们还讨论了短伽玛暴可能来源的内在性质的几个含义，例如喷流结构、内在亮度函数和内在持续时间分布。
We study the properties of short gamma-ray bursts (GRBs), based on the assumption that they are all connected to binary neutron star mergers, whose mechanism contains a large amount of uncertainty. In particular, the merger time distribution, which is essential for short GRB rate estimation, is focused on; we parametrize it simply as Pm(t)∝tα with a lower cut-off timescale τ. The short GRB rate, calculated using such a parametrization with a specific model of the cosmic star formation rate, is found to be quite insensitive to the value of τ, but very sensitive to α. With such formation rate models, the peak flux distribution observed by BATSE is fitted. In the fitting process, the local short GRB rate ρ0 is treated as one of the free parameters, giving the best fit when ρ0 = 0.1–2 yr−1 Gpc−3, depending on the other free parameters as well as the formation rate model represented by (τ,α). We also discuss several implications for the intrinsic properties of possible sources of short GRBs, such as jet structure, intrinsic luminosity function, and intrinsic duration distribution.