Survey of gravitational wave memory in intermediate mass ratio binaries
Survey of gravitational wave memory in intermediate mass ratio binaries
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DOI：
10.1103/physrevd.108.024046
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发表时间：
2021-09
影响因子：
5
通讯作者：
Tousif Islam;Scott E. Field;G. Khanna;Niels Warburton
中科院分区：
文献类型：
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作者：
Tousif Islam;Scott E. Field;G. Khanna;Niels Warburton
非线性引力波(GW)记忆效应是广义相对论中一个独特的预言。虽然对于类似质量的双星，这种影响已经得到了很好的研究，但在中等质量比激发星(IMRIS)中，这种影响大多被忽视了。我们全面分析了由恒星质量黑洞和中等质量黑洞组成的重IMRIS中记忆效应的现象学和可探测性，包括次优谐模式的贡献。当通过分级合并形成IMRI系统时，例如当类似GW190521的残骸捕获一个恒星质量黑洞时，IMRI系统具有巨大的总质量、主星上的大自转以及可能的残余偏心；这些特征可能会增加记忆检测的可能性。我们从黑洞微扰理论框架中计算的引力波计算位移和自旋非线性GW记忆，该理论部分校准为数值相对论波形。我们探讨了记忆效应对质量比、自旋和偏心率的依赖关系，并考虑了使用当前和未来的GW探测器对来自IMRIS的记忆信号的可检测性。我们发现：(I)虽然偏心率在位移记忆和自旋记忆中都引入了额外的特征，但它并没有明显改变可探测的前景，(Ii)在记忆计算中加入更高的模式可以使信噪比(SNR)在某些情况下增加约7%，(Iii)随着自旋接近较大的正值，来自位移记忆的SNR显著增加，(Iv)来自重IMRIS的自旋记忆将很难用下一代探测器检测到，即使是来自高自旋的系统。我们的结果表明，分层的二元黑洞合并可能是检测内存的一个有前途的来源，并可能有利地影响内存预测。
The non-linear gravitational wave (GW) memory effect is a distinct prediction in general relativity. While the effect has been well studied for comparable mass binaries, it has mostly been overlooked for intermediate mass ratio inspirals (IMRIs). We offer a comprehensive analysis of the phenomenology and detectability of memory effects, including contributions from subdominant harmonic modes, in heavy IMRIs consisting of a stellar mass black hole and an intermediate mass black hole. When formed through hierarchical mergers, for example when a GW190521-like remnant captures a stellar mass black hole, IMRI systems have a large total mass, large spin on the primary, and possibly residual eccentricity; features that potentially raise the prospect for memory detection. We compute both the displacement and spin non-linear GW memory from the $m \neq 0$ gravitational waveforms computed within a black hole perturbation theory framework that is partially calibrated to numerical relativity waveforms. We probe the dependence of memory effects on mass ratio, spin, and eccentricity and consider the detectability of a memory signal from IMRIs using current and future GW detectors. We find that (i) while eccentricity introduces additional features in both displacement and spin memory, it does not appreciatively change the prospects of detectability, (ii) including higher modes into the memory computation can increase singal-to-noise (SNR) values by about 7\% in some cases, (iii) the SNR from displacement memory dramatically increases as the spin approaches large, positive values, (iv) spin memory from heavy IMRIs would, however, be difficult to detect with future generation detectors even from highly spinning systems. Our results suggest that hierarchical binary black hole mergers may be a promising source for detecting memory and could favorably impact memory forecasts.