Effects of nonquadrupole modes in the detection and parameter estimation of black hole binaries with nonprecessing spins

TL;DR

This paper investigates how ignoring nonquadrupole modes in gravitational wave templates affects detection efficiency and parameter accuracy for black hole binaries with nonprecessing spins, highlighting significant impacts for certain mass ratios and spins.

Contribution

It provides a comprehensive analysis of the impact of nonquadrupole modes on GW detection and parameter estimation, offering guidelines for when these modes must be included.

Findings

Neglecting nonquadrupole modes causes significant detection loss for massive, high mass-ratio binaries.

Ignoring subdominant modes leads to larger detection loss for aligned-spin binaries.

Quadrupole-mode templates bias parameter estimates more for anti-aligned spin binaries.

Abstract

We study the effect of nonquadrupolar modes in the detection and parameter estimation of gravitational waves (GWs) from black hole binaries with nonprecessing spins, using Advanced LIGO. We evaluate the loss of the signal-to-noise ratio (SNR) and the systematic errors in the estimated parameters when a quadrupole-mode template family is used to detect GW signals with all the relevant modes. Target signals including nonquadrupole modes are constructed by matching numerical-relativity simulations of nonprecessing black hole binaries describing the late inspiral, merger and ringdown with post-Newtonian/effective-one-body waveforms describing the early inspiral. We find that neglecting nonquadrupole modes will, in general, cause unacceptable loss in the detection rate and unacceptably large systematic errors in the estimated parameters, for the case of massive binaries with large mass ratios. For a given mass ratio, neglecting subdominant modes will result in a larger loss in the detection rate for binaries with aligned spins. For binaries with antialigned spins, quadrupole-mode templates are more effectual in detection, at the cost of introducing a larger systematic bias in the parameter estimation. We provide a summary of the regions in the parameter space where neglecting nonquadrupole modes will cause an unacceptable loss of detection rates and unacceptably large systematic biases in the estimated parameters.