论文标题
由于引力 - 电磁作用而围绕超级质量黑洞徘徊
Binaries Wandering Around Supermassive Black Holes Due To Gravito-electromagnetism
论文作者
论文摘要
极端质量比率灵感（EMRIS）是太空传播引力波（GW）探测器的重要来源。这样的来源通常由恒星质量的黑洞（BH）和Kerr Supermassive BH（SMBH）组成，但是最近的天体物理模型预测，小体也可能是恒星质量的二进制BH（BBH）。达到SMBH的几个重力半径的BBH将在波形中引起丰富的可观察到的签名，但是当前的数值工具不足以模拟这种三重系统，同时捕获基本的相对论效应。在这里，我们通过研究框架中自由落在BBH旁边的动力学来解决问题。由于BBH通常是非权威主义的，并且比Kerr背景的曲率半径小得多，因此自由式框架的演变还原为牛顿动力学，除了扰动的重力 - 电磁（GEM）力是由曲线背景引起的。我们使用这种方法研究SMBH周围近圆形轨道上的BBH，并将其演变跟踪至SMBH的$ 2-3 $引力半径。我们的模拟揭示了一系列动态效应，这些效应在先前的研究中未显示使用常规方法。最值得注意的是BBH相对于SMBH的径向振荡和方位角漂移。这些结果为含有BBH的EMRI的演变和检测提供了新的见解。
Extreme-mass-ratio inspirals (EMRIs) are important sources for space-borne gravitational-wave (GW) detectors. Such a source normally consists of a stellar-mass black hole (BH) and a Kerr supermassive BH (SMBH), but recent astrophysical models predict that the small body could also be a stellar-mass binary BH (BBH). A BBH reaching several gravitational radii of a SMBH will induce rich observable signatures in the waveform, but the current numerical tools are insufficient to simulate such a triple system while capturing the essential relativistic effects. Here we solve the problem by studying the dynamics in a frame freely falling alongside the BBH. Since the BBH is normally non-relativistic and much smaller than the curvature radius of the Kerr background, the evolution in the free-fall frame reduces to essentially Newtonian dynamics, except for a perturbative gravito-electromagnetic (GEM) force induced by the curved background. We use this method to study the BBHs on near-circular orbits around a SMBH and track their evolution down to a distance of $2-3$ gravitational radii from the SMBH. Our simulations reveal a series of dynamical effects which are not shown in the previous studies using conventional methods. The most notable one is a radial oscillation and azimuthal drift of the BBH relative to the SMBH. These results provide new insight into the evolution and detection of the EMRIs containing BBHs.
