The Third-Body Imprint: Detecting Center-of-Mass Acceleration in 3G Gravitational-Wave Observations
ORAL
Abstract
The presence of a tertiary body near a coalescing binary can imprint measurable signatures on its gravitational-wave (GW) signal through center-of-mass (CoM) acceleration. A notable example is a stellar-mass binary black hole (BBH) coalescing in the vicinity of a supermassive black hole, a scenario expected to be a common occurrence in galactic nuclei and active galactic disks. The limited low-frequency sensitivity of current detectors hinders the detection of such acceleration-induced phase shifts. However, third-generation (3G) observatories such as Cosmic Explorer (CE) and the Einstein Telescope (ET), with their extended low-frequency reach, are poised to detect these subtle effects.
In this work, we explore the parameter space in which CoM acceleration significantly impacts parameter inference for stellar-mass BBHs. We find that neglecting acceleration can induce systematic biases exceeding statistical uncertainties in the estimation of chirp mass and symmetric mass ratio, even for modest accelerations of α ~ 10-9 s-1 (CE) and 10-10s-1 (ET). The effect is more pronounced for asymmetric binaries. When CoM acceleration is explicitly modeled in the waveform, accelerations of α ~ 10-7 s-1 can be constrained to within 10-9 s-1 (CE) and 10-11 s-1 (ET).
Our results highlight the importance of accounting for tertiary-induced acceleration in GW parameter estimation and demonstrate how 3G detectors can directly probe the dynamical environments and hierarchical merger pathways of binary black holes.
In this work, we explore the parameter space in which CoM acceleration significantly impacts parameter inference for stellar-mass BBHs. We find that neglecting acceleration can induce systematic biases exceeding statistical uncertainties in the estimation of chirp mass and symmetric mass ratio, even for modest accelerations of α ~ 10-9 s-1 (CE) and 10-10s-1 (ET). The effect is more pronounced for asymmetric binaries. When CoM acceleration is explicitly modeled in the waveform, accelerations of α ~ 10-7 s-1 can be constrained to within 10-9 s-1 (CE) and 10-11 s-1 (ET).
Our results highlight the importance of accounting for tertiary-induced acceleration in GW parameter estimation and demonstrate how 3G detectors can directly probe the dynamical environments and hierarchical merger pathways of binary black holes.
*Author acknowledges the support from the Infosys Foundation and from the National Science Foundation (NSF) via NSF Award No. PHY-2409372.
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Presenters
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Poulami D Dutta Roy
- University of Florida