Template Mode Hierarchies for Binary Black Hole Mergers

TL;DR

This paper explores how including higher-order modes in gravitational wave templates improves detection prospects for precessing or unequal mass binary black hole mergers, using numerical relativity simulations.

Contribution

It introduces mode hierarchies for binary black hole signals and demonstrates the importance of higher modes in detection templates for certain binary configurations.

Findings

Higher modes depend on binary characteristics and orientations.

Including higher modes enhances detection of precessing and unequal mass binaries.

Mode hierarchies can guide template bank construction.

Abstract

Matched filtering is a popular data analysis framework used to search for gravitational wave signals emitted by compact object binaries. The templates used in matched filtering searches are constructed predominantly from the quadrupolar mode because this mode is the energetically most dominant channel. However, for highly precessing binaries or binaries with moderately large mass ratios, significant power is also carried by higher-order modes. We investigate how the inclusion of higher modes in the templates increases the prospects for detecting gravitational waves. Specifically, we use numerical relativity waveforms from the late inspiral and coalescence of binary black holes to identify mode hierarchies that cover the sky of binary orientations. We show that the ordering in these hierarchies depends on the characteristics of the binary system and the mode strengths. Our study demonstrates that detecting moderately high precessing or unequal mass binaries requires the inclusion of higher modes in the templates banks.