Chi-square test on candidate events from CW signal coherent searches

TL;DR

This paper presents a method to distinguish noise artifacts from true continuous gravitational wave signals using the shape of the detection statistic, significantly reducing false candidates in broad-band searches.

Contribution

The paper introduces a new approach to differentiate noise lines from genuine signals based on the detection statistic's shape, improving candidate vetting in gravitational wave searches.

Findings

Rejects about 70% of large candidate events in a 10-hour search.

Achieves a false dismissal rate smaller than 1e-6.

Effective in data from the Hanford LIGO interferometer.

Abstract

In a blind search for continuous gravitational wave signals scanning a wide frequency band one looks for candidate events with significantly large values of the detection statistic. Unfortunately, a noise line in the data may also produce a moderately large detection statistic. In this paper, we describe how we can distinguish between noise line events and actual continuous wave (CW) signals, based on the shape of the detection statistic as a function of the signal's frequency. We will analyze the case of a particular detection statistic, the F statistic, proposed by Jaranowski, Krolak, and Schutz. We will show that for a broad-band 10 hour search, with a false dismissal rate smaller than 1e-6, our method rejects about 70 % of the large candidate events found in a typical data set from the second science run of the Hanford LIGO interferometer.