Short GRBs: Opening Angles, Local Neutron Star Merger Rate, and Off-axis Events for GRB/GW Association

	Short GRBs: Opening Angles, Local Neutron Star Merger Rate, and Off-axis Events for GRB/GW Association
	Jin, Zhi-Ping; Li, Xiang; Wang, Hao; Wang, Yuan-Zhu; He, Hao-Ning; Yuan, Qiang; Zhang, Fu-Wen; Zou, Yuan-Chuan; Fan, Yi-Zhong; Wei, Da-Ming
刊名	ASTROPHYSICAL JOURNAL
	2018
卷号	857 期号:2 页码:128
英文摘要	The jet breaks in the afterglow light curves of short gamma-ray bursts (SGRBs), rarely detected so far, are crucial for estimating the half-opening angles of the ejecta (theta(j)) and hence the neutron star merger rate. In this work, we report the detection of jet decline behaviors in GRB 150424A and GRB 160821B, and find theta j similar to 0.1 rad. Together with five events reported before 2015 and three others "identified" recently (GRB 050709, GRB 060614, and GRB 140903A), we have a sample consisting of nine SGRBs and one long-short GRB with reasonably estimated theta(j). In particular, three Swift bursts in the sample have redshifts z <= 0.2, with which we estimate the local neutron star merger rate density to be similar to 1109(-657)(+1432) Gpc(-3) yr(-1) or 162(-83)(+140) Gpc(-3) yr(-1) if the narrowly beamed GRB 061201 is excluded. Inspired by the typical theta(j) similar to 0.1 rad found currently, we further investigate whether the off-beam GRBs (in the uniform jet model) or the off-axis events (in the structured jet model) can significantly enhance the GRB/GW association. For the former, the enhancement is at most moderate, while for the latter the enhancement can be much greater and a high GRB/GW association probability of similar to 10% is possible. We also show that the data of GRB 160821B may contain a macronova/kilonova emission component with a temperature of similar to 3100 K at similar to 3.6 days after the burst and more data are needed to ultimately clarify.
语种	英语
WOS记录号	WOS:000430827000011
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/17997]
专题	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Jin, Zhi-Ping,Li, Xiang,Wang, Hao,et al. Short GRBs: Opening Angles, Local Neutron Star Merger Rate, and Off-axis Events for GRB/GW Association[J]. ASTROPHYSICAL JOURNAL,2018,857(2):128.
APA	Jin, Zhi-Ping.,Li, Xiang.,Wang, Hao.,Wang, Yuan-Zhu.,He, Hao-Ning.,...&Wei, Da-Ming.(2018).Short GRBs: Opening Angles, Local Neutron Star Merger Rate, and Off-axis Events for GRB/GW Association.ASTROPHYSICAL JOURNAL,857(2),128.
MLA	Jin, Zhi-Ping,et al."Short GRBs: Opening Angles, Local Neutron Star Merger Rate, and Off-axis Events for GRB/GW Association".ASTROPHYSICAL JOURNAL 857.2(2018):128.