Learning about compact binary merger: the interplay between numerical relativity and gravitational-wave astronomy

TL;DR

This paper explores how numerical relativity waveforms can be integrated into gravitational-wave data analysis, assessing their accuracy, sensitivity to errors, and implications for detecting and interpreting signals from black hole mergers.

Contribution

It introduces measures for waveform accuracy, estimates the number of templates needed for detection, and discusses systematic errors and computational costs in numerical simulations.

Findings

Approximately 100 templates are needed for detection with initial LIGO.

Sensitivity of data analysis to waveform errors is quantified.

Systematic errors and computational costs are estimated for future simulations.

Abstract

Activities in data analysis and numerical simulation of gravitational waves have to date largely proceeded independently. In this work we study how waveforms obtained from numerical simulations could be effectively used within the data analysis effort to search for gravitational waves from black hole binaries. We propose measures to quantify the accuracy of numerical waveforms for the purpose of data analysis and study how sensitive the analysis is to errors in the waveforms. We estimate that ~100 templates (and ~10 simulations with different mass ratios) are needed to detect waves from non-spinning binary black holes with total masses in the range 100 Msun < M < 400 Msun using initial LIGO. Of course, many more simulation runs will be needed to confirm that the correct physics is captured in the numerical evolutions. From this perspective, we also discuss sources of systematic errors in numerical waveform extraction and provide order of magnitude estimates for the computational cost of simulations that could be used to estimate the cost of parameter space surveys. Finally, we discuss what information from near-future numerical simulations of compact binary systems would be most useful for enhancing the detectability of such events with contemporary gravitational wave detectors and emphasize the role of numerical simulations for the interpretation of eventual gravitational-wave observations.