Doppler correlation-driven vetoes for the Frequency Hough analysis in continuous gravitational-wave searches

TL;DR

This paper introduces a new Doppler correlation-based veto method for continuous gravitational-wave searches that improves candidate rejection and sensitivity estimation in the Frequency Hough pipeline, validated through simulations.

Contribution

The paper presents a novel veto technique leveraging Earth Doppler-induced parameter correlations, enhancing candidate rejection and sensitivity in all-sky continuous gravitational-wave searches.

Findings

Vetoes approximately 56% of candidates on average.

Achieves a 90% confidence strain amplitude upper limit of 3.62×10^{-26} in the 128-200 Hz band.

Method calibration is linked to the total observing run duration.

Abstract

We present an improved method for vetoing candidates of continuous gravitational-wave sources during all-sky searches utilizing the Frequency Hough pipeline. This approach leverages linear correlations between source parameters induced by the Earth Doppler effect, which can be effectively identified through the Hough Transform. Candidates that do not align with these patterns are considered spurious and can thus be vetoed, enhancing the depth and statistical significance of follow-up analyses. Additionally, we provide a comprehensive explanation of the method calibration, which intrinsically linked to the total duration of the observing run. On average, the procedure successfully vetoes $56\%$ of candidates. To assess the method performance, we conducted a Monte-Carlo simulation injecting fake continuous-wave signals into data from the third observing run of the LIGO detectors. This analysis allowed us to infer strain amplitude upper limits at a $90\%$ confidence level. We found that the optimal sensitivity is $h_0^{90\%} = 3.62^{+0.23}_{-0.22}\times 10^{-26}$ in the [128, 200] Hz band, which is within the most sensible frequency band of the LIGO detectors.