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arXiv · 2405.07113

Observability of gravitational waves excited by binary stars orbiting around a supermassive black hole by space-based gravitational wave observatory

Kun Meng·Hongsheng Zhang·Xi-Long Fan·Yuan Yong·Fei Du
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Abstract

We produce the gravitational waveforms for the extreme mass ratio inspiral systems (EMRIs) of binary stars moving around central supermassive black hole (SBH), or called B-EMRIs. We calculate the external orbits of the binary stars via the commonly used Hamilton-Jacobi (HJ) approach, and calculate the internal orbits of the binary stars via Lagrangian approach. To improve accuracy we adopt the quadrupole-octupole expression of gravitational wave (GW) and study the contribution of radiation reaction. Compared to the waveforms of EMRIs, there are higher frequency oscillations superposed on the waveforms of B-EMRIs. We perform frequency spectrum analysis of the GW waveforms, and find that higher frequency signals give their prominency in the waveforms of B-EMRIs. To obtain high precise result for future observation of GWs from space-based detector, we take into account gravito-electromagnetic (GEM) force, and compare the waveforms of B-EMRIs with GEM effects against those of B-EMRIs without GEM effects and against those of EMRIs. The result of mismatch shows that the waveforms of B-EMRIs are credibly distinguishable by the space-based GW detectors when GEM force is considered.

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Kun Meng, Hongsheng Zhang, Xi-Long Fan, Yuan Yong, Fei Du. 2026-03-10. Observability of gravitational waves excited by binary stars orbiting around a supermassive black hole by space-based gravitational wave observatory. https://arxiv.org/abs/2405.07113

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