Where Binary Neutron Stars Merge: Predictions from IllustrisTNG
Where Binary Neutron Stars Merge: Predictions from IllustrisTNG
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DOI：
10.3847/1538-4357/abe405
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
J. Rose;P. Torrey;K. H. Lee;I. Bartos
中科院分区：
文献类型：
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作者：
J. Rose;P. Torrey;K. H. Lee;I. Bartos
中子星星（BNS）合并的速率和位置由星星的形成历史和延迟时间分布（DTD）函数的组合决定。在本文中，我们耦合的星星形成率的历史从IllustrisTNG模型的一系列不同的假设BNS的DTD作出预测的BNS合并宿主星系的质量函数。这些预测提供了两个结果：（i）在短期内，他们影响的BNS合并事件的后续战略，仔细检查大多数BNS合并事件预计发生，（ii）在长期内，他们约束的DTD BNS合并事件一旦主机星系质量函数是观测确定。从我们的基准模型分析，我们预测50%的BNS合并将发生在恒星质量在1010和1011 M <$A之间的宿主星系中，68%在4 × 109和3 × 1011 M <$A之间，95%在4 × 108和2 × 1012 M <$A之间。我们发现，所采用的DTD的细节上的主机质量函数的峰值没有很强的影响。然而，变化的DTD提供了足够的扩展，真正的DTD可以确定从足够的电磁观测BNS合并。了解真正的DTD可以帮助我们确定通过高度偏心和短分离快速合并通道形成的BNS系统的流行程度，并可以限制r-过程材料的主要来源。
The rate and location of binary neutron star (BNS) mergers are determined by a combination of the star formation history and the delay-time distribution (DTD) function. In this paper, we couple the star formation rate histories from the IllustrisTNG model to a series of varied assumptions for the BNS DTD to make predictions for the BNS merger host galaxy mass function. These predictions offer two outcomes: (i) in the near term they influence the BNS merger event follow-up strategy by scrutinizing where most BNS merger events are expected to occur, and (ii) in the long term they constrain the DTD for BNS merger events once the host galaxy mass function is observationally well determined. From our fiducial model analysis, we predict that 50% of BNS mergers will occur in host galaxies with stellar mass between 1010 and 1011 M ⊙, 68% between 4 × 109 and 3 × 1011 M ⊙, and 95% between 4 × 108 and 2 × 1012 M ⊙. We find that the details of the DTD employed do not have a strong effect on the peak of the host mass function. However, varying the DTD provides enough spread that the true DTD can be determined from enough electromagnetic observations of BNS mergers. Knowing the true DTD can help us determine the prevalence of BNS systems formed through highly eccentric and short-separation fast-merging channels and can constrain the dominant source of r-process material.