Constraining Short Gamma-Ray Burst Jet Properties with Gravitational Waves and Gamma-Rays
Constraining Short Gamma-Ray Burst Jet Properties with Gravitational Waves and Gamma-Rays
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DOI：
10.3847/1538-4357/ab7eaf
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
S. Biscoveanu;E. Thrane;S. Vitale
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文献类型：
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作者：
S. Biscoveanu;E. Thrane;S. Vitale
伽马射线暴（GRB）的瞬发是高度波束的，了解喷流的几何形状和波束结构可以为我们提供一些鲜为人知的中央发动机和周边环境的信息。在引力波天文学出现之前，天文学家依靠观察多波长余辉中的喷流破裂来确定GRB的开启角度，因为观测者相对于系统的视角不能单独从电磁数据确定。然而，引力波观测提供了一个独立的视角测量。我们描述了一种贝叶斯方法来确定短伽马射线暴（sgrb）的几何形状，使用重合的电磁和引力波观测。我们演示了如何使用多信使探测集合来测量sgrb的射流能量、开口角、洛伦兹因子和角剖面的分布；我们发现，对于100个这样的观测值，我们可以将开口角分布的平均值限制在10°以内，而不考虑角发射剖面。相反，对能量分布的约束取决于轮廓的形状，这是可以区分的。
Gamma-ray burst (GRB) prompt emission is highly beamed, and understanding the jet geometry and beaming configuration can provide information on the poorly understood central engine and circumburst environment. Prior to the advent of gravitational-wave astronomy, astronomers relied on observations of jet breaks in the multiwavelength afterglow to determine the GRB opening angle, since the observer’s viewing angle relative to the system cannot be determined from the electromagnetic data alone. Gravitational-wave observations, however, provide an independent measurement of the viewing angle. We describe a Bayesian method for determining the geometry of short GRBs (sGRBs) using coincident electromagnetic and gravitational-wave observations. We demonstrate how an ensemble of multimessenger detections can be used to measure the distributions of the jet energy, opening angle, Lorentz factor, and angular profile of sGRBs; we find that for a population of 100 such observations, we can constrain the mean of the opening angle distribution to within 10° regardless of the angular emission profile. Conversely, the constraint on the energy distribution depends on the shape of the profile, which can be distinguished.