标题： Illustris中的三重大质量黑洞系统的合并与反冲 显示英文标题

标题： Mergers and Recoil in Triple Massive Black Hole Systems from Illustris

摘要： 大质量黑洞双星（MBHBs）通过星系合并形成，是宇宙中最强烈的引力波（GWs）源之一。 如果双星的螺旋运动时间较长，后续的星系合并可能会引入第三个黑洞，形成三体系统。 在Illustris宇宙学模拟中，6%的大质量黑洞双星在毫秒尺度上形成了这样的三体系统，在这种尺度下强三体相互作用很可能发生。 我们将三体黑洞数值模拟的结果应用于Illustris中识别出的强三体系统，以评估它们对MBH合并和反冲的影响。 我们发现，强烈的三体相互作用使总体合并分数增加了4%。 包括三体相互作用后，相对于孤立地建模双星演化，强三体系统中MBH的合并分数从40%提高到69%。 此外，大规模的主要星系合并比一般合并更可能受到强烈三体相互作用的促进，可能性超过三倍。 我们还比较了引力波反冲和三体相互作用产生的引力弹弓反冲。 这两种机制都能产生超过宿主逃逸速度的反冲，将MBH弹射出去，产生漂移或偏移的黑洞。 尽管弹弓效应产生的反冲速度最高，但在假设随机MBH自旋方向的情况下，引力波反冲主导了被弹射出去的黑洞群体。 在这种假设下，由引力波反冲和弹弓效应引起的弹射将合并总数减少了6%。 我们的研究结果强调了强烈的三体动力学和引力波反冲对MBH演化的影响，并支持将其纳入宇宙学模拟中。 显示英文摘要

摘要： Massive black hole binaries (MBHBs) form through galaxy mergers and are among the loudest sources of gravitational waves (GWs) in the universe. If the binary inspiral time is long, a subsequent galaxy merger can introduce a third black hole, forming a triple system. In the Illustris cosmological simulation, 6% of MBHBs form such triples at parsec scales, where strong three-body interactions are likely. We apply results from numerical simulations of triple MBHs to strong triples identified in Illustris to assess their impact on MBH mergers and recoils. We find that strong triple interactions increase the overall merger fraction by 4%. Including triple interactions raises the merger fraction of MBHs in strong triple systems from 40% to 69%, relative to modeling binary evolution in isolation. Furthermore, massive, major mergers are over three times more likely to be facilitated by strong triple interactions than mergers in general. We also compare GW recoil kicks to gravitational slingshot kicks from triple interactions. Both mechanisms can produce kicks exceeding host escape speeds, ejecting MBHs and producing wandering or offset black holes. Although slingshots yield the highest velocity kicks, GW recoils dominate the ejected population when assuming random MBH spin orientations. Under this assumption, ejections from GW recoil and slingshot kicks reduce the total number of mergers by 6%. Our results highlight the impact of strong triple dynamics and GW recoils on MBH evolution and support their inclusion in cosmological simulations.