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arXiv 1602.02363astro-ph.HEastro-ph.COhep-ph
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已知红移的伽马射线暴观测持续时间和本征持续时间的分析

Analysis of the observed and intrinsic durations of gamma-ray bursts with known redshift

Mariusz Tarnopolski

摘要:

检查了408个伽玛暴的持续时间分布,测量了持续时间$T_{90}$和红移$z$。使用最大对数似然法将许多分布(标准正态、偏态、sinh-arcsinh和alpha-斜态)的混合拟合到观察持续时间和内在持续时间。通过赤池信息标准选择最佳拟合。这项工作的目的是评估假设的中间伽玛暴类的存在,并提供一个现象学模型比常见的混合标准高斯更合适。虽然$\log T^{obs}_{90}$是由一个真正的三峰拟合很好地描述,移动到休息帧后,统计上最显着的拟合是单峰。为了追踪这种差异的来源,我们用同样的方法检验了仅由$Swift$ /BAT观测到的334个伽玛暴。在观察者框架中,这导致了许多统计上合理的描述,是单模态和双模态的,并且分量的数量从一到三不等。在移动到静止框架之后,可能不会提出明确的结论。它的结论是,样本的大小是不够大的,以可靠地推断伽玛暴的性质的基础上,单变量的统计推理。

英文摘要:

The duration distribution of 408 GRBs with measured both duration $T_{90}$ and redshift $z$ is examined. Mixtures of a number of distributions (standard normal, skew-normal, sinh-arcsinh, and alpha-skew-normal) are fitted to the observed and intrinsic durations using the maximum log-likelihood method. The best fit is chosen via the Akaike information critetion. The aim of this work is to assess the presence of the presumed intermediate GRB class, and to provide a phenomenological model more appropriate than the common mixture of standard Gaussians. While $\log T^{obs}_{90}$ are well described by a truly trimodal fit, after moving to the rest frame the statistically most significant fit is unimodal. To trace the source of this discrepancy, 334 GRBs observed only by $Swift$/BAT are examined in the same way. In the observer frame, this results in a number of statistically plausible descriptions, being uni- and bimodal, and with the number of components ranging from one to three. After moving to the rest frame, no unambiguous conclusions may be put forward. It is concluded that the size of the sample is not big enough to infer reliably GRB properties based on a univariate statistical reasoning only.

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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