Tidal Disruptions of Stars by Black Hole Remnants in Dense Star Clusters
Tidal Disruptions of Stars by Black Hole Remnants in Dense Star Clusters
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DOI：
10.3847/1538-4357/ab2e0c
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发表时间：
2019-04
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影响因子：
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通讯作者：
K. Kremer;Wenbin Lu;C. Rodriguez;Mitchell Lachat;F. Rasio
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作者：
K. Kremer;Wenbin Lu;C. Rodriguez;Mitchell Lachat;F. Rasio
在稠密的恒星环境中，如球状星团（GC）的核心，与黑洞（BH）的动力学相互作用预计将导致各种天体物理瞬变。在这里，我们探讨恒星质量黑洞通过碰撞和近距离接触的恒星潮汐破裂事件（TDE）。使用国家的最先进的集群模拟，我们表明，这些TDE发生在整个典型的GC的演变显着的速率，我们研究它们的相对速率与集群参数，如质量和大小。通过结合GC形成的现实宇宙学模型，我们预测在本宇宙（z < 0.1）中BH-主序星的TDE速率约为3 Gpc−3 yr−1，而在红移为3时，宇宙学速率的峰值约为25 Gpc−3 yr−1。此外，我们还发现，与这些TDEs相关的喷射物质可以产生光度为1041 - 1044 erg s-1的光学瞬变，时间尺度约为一天到一个月。这些应该很容易通过光学瞬变测量（如Zwicky Transient Facility）检测到。最后，我们简要地评论BH-巨星的遭遇，并讨论如何这些事件可能有助于BH-白矮星双星的形成。
In a dense stellar environment, such as the core of a globular cluster (GC), dynamical interactions with black holes (BHs) are expected to lead to a variety of astrophysical transients. Here we explore tidal disruption events (TDEs) of stars by stellar-mass BHs through collisions and close encounters. Using state-of-the-art cluster simulations, we show that these TDEs occur at significant rates throughout the evolution of typical GCs and we study how their relative rates relate to cluster parameters such as mass and size. By incorporating a realistic cosmological model of GC formation, we predict a BH–main-sequence-star TDE rate of approximately 3 Gpc−3 yr−1 in the local universe (z < 0.1) and a cosmological rate that peaks at roughly 25 Gpc−3 yr−1 for redshift 3. Furthermore, we show that the ejected mass associated with these TDEs could produce optical transients of luminosity ∼1041−1044 erg s−1 with timescales of about a day to a month. These should be readily detectable by optical transient surveys such as the Zwicky Transient Facility. Finally, we comment briefly on BH–giant encounters and discuss how these events may contribute to the formation of BH–white-dwarf binaries.