The merger of a binary black hole gives birth to a highly distorted final black hole. The gravitational radiation emitted as this black hole relaxes presents us with the unique opportunity to probe extreme gravity and its connection with the dynamics of the black hole horizon. Using numerical relativity simulations, we demonstrate a connection between a concrete observable feature in the gravitational waves and geometrical features on the dynamical apparent horizon of the final black hole. Specifically, we show how the line-of-sight passage of a “cusp”-like defect on the horizon of the final black hole correlates with “chirp”-like frequency peaks in the post-merger gravitational-waves. These post-merger chirps should be observed and analyzed as the sensitivity of LIGO and Virgo increase and as future generation detectors, such as LISA and the Einstein Telescope, become operational.

二进制黑洞的合并产生了高度失真的最终黑洞。黑洞放松时发出的引力辐射为我们提供了探索极端重力及其与黑洞视界动力学的联系的独特机会。使用数值相对论模拟，我们证明了引力波中的具体可观察特征与最终黑洞动态视界上的几何特征之间的联系。具体来说，我们显示了最终黑洞地平线上“尖峰”状缺陷的视线通道与合并后引力波中“线性调频”状频率峰如何相关。随着LIGO和处女座的灵敏度的提高以及下一代探测器的出现，应当对这些合并后的should声进行观察和分析。