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arXiv 2107.09475astro-ph.HE
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用CHIME探测中子星合并的长时射电瞬变

On the use of CHIME to Detect Long-Duration Radio Transients from Neutron Star Mergers

Minori Shikauchi, Kipp Cannon, Haoxiang Lin, Tomonori Totani, J. Richard Shaw

摘要:

GRB 170817 A的短伽马射线暴(SGRB)被发现与一个双星中子星(BNS)合并有关。目前尚不确定是否所有SGRB都是由BNS合并引起的,也不确定BNS合并在什么条件下会引起SGRB。由于BNS合并可能导致SGRB,余辉观测也将提供一种独立于引力波观测的BNS合并率的替代测量。在Feng等人(2014)之前的工作中,使用各种无线电观测站和简单的通量阈值检测算法来考虑余辉检测的可行性。在这里,我们考虑一个更复杂的检测算法SGRB余辉,并提供一个现实的搜索,以获得一个更新的估计与加拿大氢强度测绘实验(CHIME)观测余辉的可能性的试验因素的估计。我们估计每年893和312余辉可以检测到使用$3 σ$置信水平阈值与两个喷流模型,一个半开角均匀分布在$6^\circ$到$30^\circ$,另一个均匀分布在$3^\circ$到$8^\circ$与中位数$6^\circ$。我们还发现,88%和98%,分别为每个射流开口分布的可检测的余辉是离轴的,这是孤儿余辉的候选人。我们的结果预测每年可检测到的源比早期的分析少,但证实了使用CHIME搜索余辉将有效限制天体物理合并率的基本结论。

英文摘要:

Short gamma-ray burst (SGRB) GRB 170817A was found to be related to a binary neutron star (BNS) merger. It is uncertain whether all SGRBs are caused by BNS mergers, and also under what conditions a BNS merger can cause a SGRB. As BNS mergers can cause SGRBs, afterglow observations will also provide an alternative measurement of the BNS merger rate independent of gravitational-wave observations. In previous work by Feng et al. (2014), the feasibility of the detection of afterglows was considered using a variety of radio observatories and a simple flux threshold detection algorithm. Here, we consider a more sophisticated detection algorithm for SGRB afterglows, and provide an estimate of the trials factors for a realistic search to obtain an updated estimate of the possibility of observing afterglows with the Canadian Hydrogen Intensity Mapping Experiment (CHIME). We estimate 893 and 312 afterglows per year can be detected using a $3 σ$ confidence level threshold with two jet models, one with half opening angle uniformly distributed in $6^\circ$ to $30^\circ$ and the other uniformly distributed in $3^\circ$ to $8^\circ$ with the median $6^\circ$. We also find 88% and 98%, respectively, of the detectable afterglows for each jet opening distribution are off-axis, which are candidates for orphan afterglows. Our result predicts fewer detectable sources per year than the earlier analysis, but confirms the essential conclusion that using CHIME to search for afterglows will be effective at constraining the astrophysical merger rate.

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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