Binary black holes in the heat of merger

TL;DR

This paper models tidal heating effects in binary black hole mergers using numerical relativity data, leading to improved waveform approximants that incorporate horizon parameters and are relevant for gravitational wave detection.

Contribution

It introduces a frequency-domain approximant for nonspinning black hole binaries that accounts for tidal heating effects up to merger, enhancing waveform accuracy.

Findings

The model captures tidal heating effects in the strong gravity regime.

Inclusion of horizon parameters allows for more accurate waveform modeling.

Application to neutron star systems discussed.

Abstract

A black hole binary approaching merger undergoes changes in its inspiral rate as energy and angular momentum are lost from the orbits into the horizons. This effect strengthens as the black holes come closer. We use numerical relativity data to model this so-called tidal heating in the strong gravity regime. We present a frequency-domain approximant for nonspinning black hole binaries that accounts for tidal heating effects up to the merger frequency. The approximant includes horizon parameters that characterize the nature of the compact objects. By applying this model to a binary black hole baseline that incorporates tidal heating, one can construct a more accurate point-particle waveform, one that is devoid of finite-size effects of the component objects. We also discuss its ramifications in modeling binary neutron star systems.