标题： 超大质量黑洞周围的黑洞双星的诞生、生存和死亡：引力波源的动力学演化 显示英文标题

标题： Birth, life, and death of black hole binaries around supermassive black holes: dynamical evolution of gravitational wave sources

摘要： 本文中，我们探讨了调节围绕超大质量黑洞（SMBH）形成和演化的恒星级黑洞双星（BHBs）的机制。我们表明，如果SMBH周围存在一个质量较大的核球（NC），动态相互作用可以有效地驱动“就地”BHB的形成；而轨道分离的恒星团则可以在SMBH主导的核区补充BHB的储备库。我们讨论了恒星硬化与质量分离共同作用如何塑造BHB的轨道属性。我们使用包含至2.5阶后牛顿修正的直接N体模拟来研究BHB-SMBH的相互作用，表明Kozai-Lidov机制在缩短双星寿命方面起着关键作用。我们发现，在$10^6-10^9{\rm ~M}_\odot$质量范围内，合并概率对SMBH质量的依赖较弱，导致红移为零时的合并率为$\Gamma \simeq 3-8$年$^{-1}$Gpc$^{-3}$。近$40\%$的合并事件具有“黑洞质量间隙”内的质量，即$50-140{\rm ~M}_\odot$，这表明星系核区是形成这一质量范围黑洞的理想场所。 我们认为质量分别为$m_1>40{\rm ~M}_\odot$和$m_2<30{\rm ~M}_\odot$的引力波 (GW) 源将是星系核起源的有力指示器。 这些合并事件中的大多数可能是局部宇宙中的多频段引力波源：近$40\%$个可能会被 LISA 视为偏心源，并在几年后由 LIGO 和爱因斯坦望远镜视为圆轨道源，使像 DECIGO 这样的十赫兹观测台成为连接双星吸积过程观测的独特工具。 显示英文摘要

摘要： In this paper, we explore the mechanisms that regulate the formation and evolution of stellar black hole binaries (BHBs) around supermassive black holes (SMBHs). We show that dynamical interactions can efficiently drive "in-situ" BHB formation if the SMBH is surrounded by a massive nuclear cluster (NC), while orbitally segregated star clusters can replenish the BHB reservoir in SMBH-dominated nuclei. We discuss how the combined action of stellar hardening and mass segregation sculpts the BHB orbital properties. We use direct N-body simulations including post-Newtonian corrections up to 2.5 order to study the BHB-SMBH interplay, showing that the Kozai-Lidov mechanism plays a crucial role in shortening binaries lifetime. We find that the merging probability weakly depends on the SMBH mass in the $10^6-10^9{\rm ~M}_\odot$ mass range, leading to a merger rate $\Gamma \simeq 3-8$ yr$^{-1}$ Gpc$^{-3}$ at redshift zero. Nearly $40\%$ of the mergers have masses in the "BH mass gap", $50-140{\rm ~M}_\odot$, thus indicating that galactic nuclei are ideal places to form BHs in this mass range. We argue that gravitational wave (GW) sources with components mass $m_1>40{\rm ~M}_\odot$ and $m_2<30{\rm ~M}_\odot$ would represent a strong indicator of a galactic nuclei origin. The majority of these mergers could be multiband GW sources in the local Universe: nearly $40\%$ might be seen by LISA as eccentric sources and, a few years later, as circular sources by LIGO and the Einstein Telescope, making decihertz observatories like DECIGO unique instruments to bridge the observations during the binary inspiral.