Remnant of binary black-hole mergers: New simulations and peak luminosity studies

TL;DR

This paper presents 71 new numerical simulations of binary black hole mergers, improving empirical models for remnant properties and introducing a new formula for peak gravitational wave luminosity, aiding gravitational wave data analysis.

Contribution

The study provides enhanced empirical formulas for remnant black hole mass, spin, recoil, and introduces a peak luminosity formula, based on extensive new simulations covering diverse binary parameters.

Findings

High-accuracy fits for remnant mass and spin (0.1-0.2% errors)

Recoil velocity estimates within 5% accuracy

New peak luminosity formula validated against simulations

Abstract

We present the results of 61 new simulations of nonprecessing spinning black hole binaries with mass ratios $q=m_1/m_2$ in the range $1/3\leq q\leq1$ and individual spins covering the parameter space $-0.85\leq\alpha_{1,2}\leq0.85$. We additionally perform 10 new simulations of nonspinning black hole binaries with mass ratios covering the range $1/6\leq q<1$. We follow the evolution for typically the last ten orbits before merger down to the formation of the final remnant black hole. This allows for assessment of the accuracy of our previous empirical formulae for relating the binary parameters to the remnant final black hole mass, spin and recoil. We use the new simulation to improve the fit to the above remnant formulae and add a formula for the peak luminosity of gravitational waves, produced around the merger of the two horizons into one. We find excellent agreement (typical errors $\sim0.1-0.2\%$) for the mass and spin, and within $\sim5\%$ for the recoil and peak luminosity. These formulae have direct application to parameter estimation techniques applied to LIGO observations of gravitational waves from binary black hole mergers.