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arXiv 2202.01191astro-ph.HE
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GRB 210217A:一个短暴还是长暴?

GRB 210217A: A short or a long GRB?

Dimple, Kuntal Misra, Ankur Ghosh, K. G. Arun, Rahul Gupta, Amit Kumar, L. Resmi, S. B. Pandey, Lallan Yadav

AI总结:

针对GRB 210217A被不同仪器分类为长暴或短暴的问题,利用多波长数据通过多种分布分析和光度红移估计,发现其兼具两类性质,属于模糊暴。

摘要:

伽马射线暴传统上根据其$T_{\rm 90}$值(仪器观测到伽马射线/硬X射线注量的5%至95%的时间间隔)分为短暴和长暴。然而,$T_{\rm 90}$依赖于探测器的灵敏度和仪器工作的能量范围。因此,不同的仪器对同一暴发给出不同的$T_{\rm 90}$值。GRB 210217A被{\it Swift}和{\it Fermi}探测到不同的持续时间。{\it Swift}-BAT将其归类为长/软伽马射线暴,$T_{\rm 90}$值为3.76秒。另一方面,{\it Fermi}-GBM的亚阈值探测将GRB 210217A归类为短/硬暴,持续时间为1.024秒。我们利用多波长数据对GRB 210217A(位于长暴和短暴的重叠区域)进行了多波长分析,以确定其实际类别。我们利用伽马射线暴的$T_{\rm 90}$-硬度比、$T_{\rm 90}$-$E_{\rm p}$和$T_{\rm 90}$-$t_{\rm mvts}$分布来寻找GRB 210217A为短暴的概率。此外,我们通过拟合XRT/UVOT联合谱能量分布估算了该暴的光度红移,并将其置于Amati平面上。我们发现GRB 210217A是一个模糊的暴,同时表现出短暴和长暴的性质。

英文摘要:

Gamma-ray bursts are traditionally classified as short and long bursts based on their $T_{\rm 90}$ value (the time interval during which an instrument observes $5\%$ to $95\%$ of gamma-ray/hard X-ray fluence). However, $T_{\rm 90}$ is dependent on the detector sensitivity and the energy range in which the instrument operates. As a result, different instruments provide different values of $T_{\rm 90}$ for a burst. GRB 210217A is detected with different duration by {\it Swift} and {\it Fermi}. It is classified as a long/soft GRB by {\it Swift}-BAT with a $T_{\rm 90}$ value of 3.76 sec. On the other hand, the sub-threshold detection by {\it Fermi}-GBM classified GRB 210217A as a short/hard burst with a duration of 1.024 sec. We present the multi-wavelength analysis of GRB 210217A (lying in the overlapping regime of long and short GRBs) to identify its actual class using multi-wavelength data. We utilized the $T_{\rm 90}$-hardness ratio, $T_{\rm 90}$-\Ep, and $T_{\rm 90}$-$t_{\rm mvts}$ distributions of the GRBs to find the probability of GRB 210217A being a short GRB. Further, we estimated the photometric redshift of the burst by fitting the joint XRT/UVOT SED and place the burst in the Amati plane. We found that GRB 210217A is an ambiguous burst showing properties of both short and long class of GRBs.

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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