An analysis of the durations of Swift gamma-ray bursts
An analysis of the durations of Swift gamma-ray bursts
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DOI：
10.1051/0004-6361:20079210
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发表时间：
2007-08
影响因子：
6.5
通讯作者：
Zhibin Zhang;C. Choi
中科院分区：
文献类型：
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作者：
Zhibin Zhang;C. Choi
上下文雨燕探测器被发现对长时间的软爆发比雨燕前的任务更敏感。这可能会在很大程度上影响持续时间的分布，从而影响伽马射线暴的分类。目标。我们系统地研究了雨燕时代与雨燕前伽玛射线暴的持续时间分布。方法.本文采用K-S检验和线性/非线性拟合分析等统计方法，对雨燕爆发在观测者和源坐标系下的持续时间特性进行了研究。结果对于95个已知红移的伽玛暴，我们证明了在T（90）等于或等于2 s时，两个持续时间的对数正态分布明显分开。固有持续时间也表现出双峰分布，但系统地向较小的值移动，并且分布的宽度比观察到的要窄。与雨燕之前的长暴相比，雨燕长暴在观测者和源帧中都表现出更宽的持续时间动态范围。结论.我们发现，雨燕爆发和前雨燕的可以共享相同的分类标准，在2秒的持续时间，虽然这两个监视器有很大的差异，相对于一个给定的能量带的灵敏度。
Context. Swift detectors are found to be more sensitive to long-soft bursts than pre-Swift missions. This may largely bias the distribution of durations and thus classification of gamma-ray bursts. Aims. We systematically investigate the duration distribution of gamma-ray bursts in the Swift era vs. that of pre-Swift bursts. Methods. For the purpose of this study, statistical methods such as the K-S test and linear/non-linear fitting analysis have been used to examine the duration properties of Swift bursts in both observer and source frames. Results. For 95 GRBs with known redshift, we show that two log-normal distributions of duration are clearly divided at T(90) similar or equal to 2 s. The intrinsic durations also show a bimodal distribution but shift systematically toward the smaller value and the distribution exhibits a narrower width than the observed one. Swift long bursts exhibit a wider duration dynamic range in both observer and source frames in comparison to pre-Swift long bursts. Conclusions. We find that Swift bursts and pre-Swift ones can share the same criterion of classification in terms of duration at 2 s, although both monitors have large differences with respect to sensitivity of a given energy band.