Leveraging NRTidalv3 to develop gravitational waveform models with higher-order modes for binary neutron star systems

TL;DR

This paper enhances gravitational waveform models for binary neutron star mergers by incorporating higher-order modes into the NRTidalv3 model, improving accuracy for next-generation detectors and aiding parameter estimation.

Contribution

It extends the NRTidalv3 model to include higher-mode tidal phase corrections and integrates it with existing binary black hole waveform models.

Findings

The new models match well with numerical-relativity simulations.

They provide consistent parameter estimates on GW170817.

Enhanced models improve accuracy for high-mass-ratio systems.

Abstract

Accurate and reliable gravitational waveform models are crucial in determining the properties of compact binary mergers. In particular, next-generation gravitational-wave detectors will require more accurate waveforms to avoid biases in the analysis. In this work, we extend the recent NRTidalv3 model to account for higher-mode corrections in the tidal phase contributions for binary neutron star systems. The higher-mode, multipolar NRTidalv3 model is then attached to several binary-black-hole baselines, such as the phenomenological IMRPhenomXHM and IMRPhenomXPHM models, and the effective-one-body-based model SEOBNRv5HM_ROM. We test the performance and validity of the newly developed models by comparing them with numerical-relativity simulations and other tidal models. Finally, we employ them in parameter estimation analyses on simulated signals from both comparable-mass and high-mass-ratio systems, as well as on the gravitational-wave event GW170817, for which we find consistent results with respect to previous analyses.