High-accuracy waveforms for binary black hole inspiral, merger, and ringdown

TL;DR

This paper presents the first spectral numerical simulations of an equal-mass non-spinning binary black hole system covering 16 orbits, merger, and ringdown, achieving high-accuracy gravitational waveforms with minimal phase errors.

Contribution

It introduces a novel spectral simulation method for binary black hole mergers with highly accurate waveforms and detailed measurements of final black hole properties.

Findings

Numerical phase errors are approximately 0.1 radians through ringdown.

Waveforms extrapolated to infinity have phase errors around 0.01 radians.

Final black hole mass ratio is approximately 0.95162, with spin about 0.68646.

Abstract

The first spectral numerical simulations of 16 orbits, merger, and ringdown of an equal-mass non-spinning binary black hole system are presented. Gravitational waveforms from these simulations have accumulated numerical phase errors through ringdown of ~0.1 radian when measured from the beginning of the simulation, and ~0.02 radian when waveforms are time and phase shifted to agree at the peak amplitude. The waveform seen by an observer at infinity is determined from waveforms computed at finite radii by an extrapolation process accurate to ~0.01 radian in phase. The phase difference between this waveform at infinity and the waveform measured at a finite radius of r=100M is about half a radian. The ratio of final mass to initial mass is M_f/M = 0.95162 +- 0.00002, and the final black hole spin is S_f/M_f^2=0.68646 +- 0.00004.