Statistical classification of gamma-ray bursts based on the Amati relation
Statistical classification of gamma-ray bursts based on the Amati relation
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DOI：
10.1093/mnras/sts547
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发表时间：
2013-03
影响因子：
4.8
通讯作者：
Y. Qin;Zhi-Fu Chen
中科院分区：
文献类型：
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作者：
Y. Qin;Zhi-Fu Chen
伽玛射线暴（GRBs）被认为分为两类，它们通常根据持续时间进行划分。由于两类的持续时间分布严重重叠，该分类方案不能令人满意。我们收集了153个新的grb样本，研究了$E_p$值与Amati关系的对数偏差分布。分布具有明显的双峰结构，可以用两条高斯曲线的组合来解释。在此基础上，我们提出用$E_p$值的对数偏差对已知的$E_{p}$和$E_{iso}$平面上的grb进行统计分类。该分类方案将grb分为两类：Amati型暴和非Amati型暴。阿玛蒂型爆发遵循阿玛蒂关系，而非阿玛蒂型爆发则不然。结果表明，大多数Amati型突发是长持续时间突发，而大多数非Amati型突发是短持续时间突发。此外，它揭示了阿玛蒂型爆发通常比非阿玛蒂型爆发更有能量。新分类方法的一个优点是，这两种类型的爆发可以很好地区分，因此它们的成员可以确定地识别出来。
Gamma-ray bursts (GRBs) are believed to belong to two classes and they are conventionally divided according to their durations. This classification scheme is not satisfied due to the fact that duration distributions of the two classes are heavily overlapped. We collect a new sample (153 sources) of GRBs and investigate the distribution of the logarithmic deviation of the $E_p$ value from the Amati relation. The distribution possesses an obvious bimodality structure and it can be accounted for by the combination of two Gaussian curves. Based on this analysis, we propose to statistically classify GRBs in the well-known $E_{p}$ vs. $E_{iso}$ plane with the logarithmic deviation of the $E_p$ value. This classification scheme divides GRBs into two groups: Amati type bursts and non-Amati type bursts. While Amati type bursts well follow the Amati relation, non-Amati type bursts do not. It shows that most Amati type bursts are long duration bursts and the majority of non-Amati type bursts are short duration bursts. In addition, it reveals that Amati type bursts are generally more energetic than non-Amati type bursts. An advantage of the new classification is that the two kinds of burst are well distinguishable and therefore their members can be identified in certainty.