Gravitational waves from plunges into Gargantua
Gravitational waves from plunges into Gargantua
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DOI：
10.1088/1361-6382/aab99e
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发表时间：
2017-12
影响因子：
3.5
通讯作者：
G. Compère;K. Fransen;T. Hertog;J. Long
中科院分区：
文献类型：
--
作者：
G. Compère;K. Fransen;T. Hertog;J. Long
我们解析计算了非自旋致密天体进入超大质量近极值克尔黑洞的极端质量比吸气最后阶段产生的时域重力波形。共形对称通过复共形变换将测地线近似中的所有旋转赤道轨道与圆轨道联系起来。利用这一方法，我们得到了封闭形式的一般赤道旋转俯冲的时域Teukolsky微扰。由此产生的重力波形包括一个中间多项式衰荡阶段，其中衰减速率取决于撞击参数，然后是指数准正态衰减。当轨道角动量趋于由最内层稳定圆轨道决定的最小值时，波形幅值表现出临界行为。我们表明，无论是接近临界的角动量还是大的角动量，都会导致LISA观测到的这类引力波源体积的显著扩展。
We analytically compute time domain gravitational waveforms produced in the final stages of extreme mass ratio inspirals of non-spinning compact objects into supermassive nearly extremal Kerr black holes. Conformal symmetry relates all corotating equatorial orbits in the geodesic approximation to circular orbits through complex conformal transformations. We use this to obtain the time domain Teukolsky perturbations for generic equatorial corotating plunges in closed form. The resulting gravitational waveforms consist of an intermediate polynomial ringdown phase in which the decay rate depends on the impact parameters, followed by an exponential quasi-normal mode decay. The waveform amplitude exhibits critical behavior when the orbital angular momentum tends to a minimal value determined by the innermost stable circular orbit. We show that either near-critical or large angular momentum leads to a significant extension of the LISA observable volume of gravitational wave sources of this kind.