Time-frequency detection of Gravitational Waves

TL;DR

This paper introduces a robust time-frequency detection method for gravitational waves that can identify poorly modeled or unmodeled signals in interferometric data, with low false alarm rates and real-time implementation.

Contribution

The authors develop and evaluate a new time-frequency detection technique that outperforms optimal filtering for certain unmodeled gravitational wave signals.

Findings

Achieves a false alarm rate of approximately 1 per 475 years for two detectors.

Single detector false dismissal rate as low as 5.3% at SNR 10.

Detects signals that are undetectable by optimal filtering under certain conditions.

Abstract

We present a time-frequency method to detect gravitational wave signals in interferometric data. This robust method can detect signals from poorly modeled and unmodeled sources. We evaluate the method on simulated data containing noise and signal components. The noise component approximates initial LIGO interferometer noise. The signal components have the time and frequency characteristics postulated by Flanagan and Hughes for binary black hole coalescence. The signals correspond to binaries with total masses between $45 M_\odot$ to $70 M_\odot$ and with (optimal filter) signal-to-noise ratios of 7 to 12. The method is implementable in real time, and achieves a coincident false alarm rate for two detectors $\approx$ 1 per 475 years. At this false alarm rate, the single detector false dismissal rate for our signal model is as low as 5.3% at an SNR of 10. We expect to obtain similar or better detection rates with this method for any signal of similar power that satisfies certain adiabaticity criteria. Because optimal filtering requires knowledge of the signal waveform to high precision, we argue that this method is likely to detect signals that are undetectable by optimal filtering, which is at present the best developed detection method for transient sources of gravitational waves.