Close encounters of stars with stellar-mass black hole binaries
Close encounters of stars with stellar-mass black hole binaries
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恒星与恒星质量黑洞双星的近距离接触
DOI：
10.1093/mnras/stac2316
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发表时间：
2022
影响因子：
4.8
通讯作者：
Wang, Yi-Han
中科院分区：
文献类型：
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作者：
Ryu, Taeho;Perna, Rosalba;Wang, Yi-Han
许多天体物理环境，从星团和球状星团到活动星系核的圆盘，都以恒星和它们留下的致密物体之间频繁的相互作用为特征。在这里，我们使用一套三维流体动力学模拟，探索引力波状态下恒星与双黑洞（BBHs）之间的密切相互作用的结果，导致潮汐破坏事件（TDE）或纯粹的散射，重点关注吸积率，对黑洞双星轨道参数的反反应，以及双星黑洞有效自旋的增加。我们发现tde可以对双星轨道产生显著的影响，这通常不同于纯粹的散射。经历顺行（逆行）TDE的二进制文件往往会被加宽（硬化）到。最初的圆形双星由于顺行或逆行的TDE而变得更偏心，而最初偏心的双星由于逆行（顺行）TDE而增加（减少）偏心。总的来说，单个TDE通常会导致引力波驱动合并时标的顺序统一变化。两个黑洞的吸积速率都是非常高的超爱丁顿，在轨道周期的时间尺度上显示出调制（特别是逆行的tde），这可能是bbh驱动的tde的特征。顺行tde的有效自旋参数χ变化为> 0.02，而逆行tde的有效自旋参数χ≥−0.005。
Many astrophysical environments, from star clusters and globular clusters to the discs of active galactic nuclei, are characterized by frequent interactions between stars and the compact objects that they leave behind. Here, using a suite of 3D hydrodynamics simulations, we explore the outcome of close interactions betweenstars and binary black holes (BBHs) in the gravitational wave regime, resulting in a tidal disruption event (TDE) or a pure scattering, focusing on the accretion rates, the back reaction on the BH binary orbital parameters, and the increase in the binary BH effective spin. We find that TDEs can make a significant impact on the binary orbit, which is often different from that of a pure scattering. Binaries experiencing a prograde (retrograde) TDE tend to be widened (hardened) by up to. Initially circular binaries become more eccentric byby a prograde or retrograde TDE, whereas the eccentricity of initially eccentric binaries increases (decreases) by a retrograde (prograde) TDE by. Overall, a single TDE can generally result in changes of the gravitational-wave-driven merger time-scale by order unity. The accretion rates of both black holes are very highly super-Eddington, showing modulations (preferentially for retrograde TDEs) on a time-scale of the orbital period, which can be a characteristic feature of BBH-driven TDEs. Prograde TDEs result in the effective spin parameter χ to vary by ≲0.02, while χ ≳ −0.005 for retrograde TDEs.