Performance of a Chirplet-based analysis for gravitational waves from binary black hole mergers

TL;DR

This paper introduces Chirplet Omega, an improved gravitational wave detection algorithm that uses chirplet templates to better match the frequency evolution of binary black hole signals, especially for lower mass systems.

Contribution

The paper presents a modified Omega algorithm incorporating chirplet templates, enhancing detection performance for binary black hole mergers in gravitational wave data.

Findings

Chirplet Omega improves signal-to-noise ratio detection capability.

Enhanced detection of lower mass black hole mergers.

Performance validated in simulated Gaussian noise at LIGO sensitivity.

Abstract

The gravitational wave (GW) signature of a binary black hole (BBH) coalescence is characterized by rapid frequency evolution in the late inspiral and merger phases. For a system with total mass larger than 100 M_sun, ground based GW detectors are sensitive to the merger phase, and the in-band whitened waveform is a short-duration transient lasting about 10-30 ms. For a symmetric mass system with total mass between 10 and 100 M_sun, the detector is sensitive instead to the inspiral phase and the in-band signal has a longer duration, between 30 ms - 3 s. Omega is a search algorithm for GW bursts that, with the assumption of locally stationary frequency evolution, uses sine-Gaussian wavelets as a template bank to decompose interferometer strain data. The local stationarity of sine-Gaussians induces a performance loss for the detection of lower mass BBH signatures, due to the mismatch between template and signal. We present the performance of a modified version of the Omega algorithm, Chirplet Omega, which allows a linear variation of frequency, to target BBH coalescences. The use of Chirplet-like templates enhances the measured signal-to-noise ratio due to less mismatch between template and data, and increases the detectability of lower mass BBH coalescences. We present the results of a performance study of Chirplet Omega in colored Gaussian noise at initial LIGO sensitivity.