The search of higher multipole radiation in gravitational waves from compact binary coalescences by a minimally-modelled pipeline

TL;DR

This paper extends the minimally-modelled coherent WaveBurst pipeline to detect higher multipole gravitational wave emissions, demonstrating its application on GW190814 to identify the (3, 3) mode during inspiral.

Contribution

It introduces a method to detect spectral features beyond the quadrupole in gravitational waves using a minimally-modelled pipeline, with application to real data.

Findings

Successful detection of the (3, 3) multipole in GW190814

Extension of cWB pipeline to analyze higher multipole modes

Validation of the method with real gravitational wave data

Abstract

The coherent WaveBurst (cWB) pipeline implements a minimally-modelled search to find a coherent response in the network of gravitational wave detectors of the LIGO-Virgo Collaboration in the time-frequency domain. In this manuscript, we provide a timely introduction to an extension of the cWB analysis to detect spectral features beyond the main quadrupolar emission of gravitational waves during the inspiral phase of compact binary coalescences; more detailed discussion will be provided in a forthcoming paper [1]. The search is performed by defining specific regions in the time-frequency map to extract the energy of harmonics of main quadrupole mode in the inspiral phase. This method has already been used in the GW190814 discovery paper (Astrophys. J. Lett. 896 L44). Here we show the procedure to detect the (3, 3) multipole in GW190814 within the cWB framework. Keywords: gravitational waves, analysis, multipoles, compact binary coalescences