A Surrogate Model for Gravitational Wave Signals from Comparable- to Large- Mass-Ratio Black Hole Binaries

TL;DR

This paper introduces EMRISur1dq1e4, a surrogate model for gravitational waveforms from black hole binaries with mass ratios from 3 to 10,000, trained on perturbation theory data, enabling analysis of high-mass ratio signals.

Contribution

The paper presents a new surrogate model that extends waveform modeling to high mass ratios up to 10,000, trained on point-particle black hole perturbation theory data.

Findings

The surrogate model covers a wider mass ratio range than previous models.

Waveforms from perturbation theory agree well with numerical relativity after mass rescaling.

The model facilitates analysis of high-mass ratio gravitational wave signals.

Abstract

Gravitational wave signals from compact astrophysical sources such as those observed by LIGO and Virgo require a high-accuracy, theory-based waveform model for the analysis of the recorded signal. Current inspiral-merger-ringdown models are calibrated only up to moderate mass ratios, thereby limiting their applicability to signals from high-mass ratio binary systems. We present EMRISur1dq1e4, a reduced-order surrogate model for gravitational waveforms of 13,500M in duration and including several harmonic modes for non-spinning black hole binary systems with mass-ratios varying from 3 to 10,000 thus vastly expanding the parameter range beyond the current models. This surrogate model is trained on waveform data generated by point-particle black hole perturbation theory (ppBHPT) both for large mass-ratio and comparable mass-ratio binaries. We observe that the gravitational waveforms generated through a simple application of ppBHPT to the comparable mass-ratio cases agree remarkably (and surprisingly) well with those from full numerical relativity after a rescaling of the ppBHPT's total mass parameter. This observation and the EMRISur1dq1e4 surrogate model will enable data analysis studies in the high-mass ratio regime, including potential intermediate mass-ratio signals from LIGO/Virgo and extreme-mass ratio events of interest to the future space-based observatory LISA.