Pearson cross-correlation in the first four black hole binary mergers

TL;DR

This paper demonstrates that Pearson cross-correlation effectively detects black hole merger signals in LIGO data, aligning with established matched-filter results and confirming the method's sensitivity to gravitational wave events.

Contribution

The study introduces the use of Pearson cross-correlation as a simple, alternative detection method for gravitational wave signals in LIGO data, validating its effectiveness against known events.

Findings

Cross-correlation peaks align with merger events.

Method's significance matches matched-filter analysis.

No residual correlation after subtracting known waveforms.

Abstract

We adopt the Pearson cross-correlation measure to analyze the LIGO Hanford and LIGO Livingston detector data streams around the events GW150914, GW151012,GW151226 and GW170104. We find that the Pearson cross-correlation method is sensitive to these signals, with correlations peaking when the black hole binaries reconstructed by the LIGO Scientific and Virgo Collaborations, are merging. We compare the obtained cross-correlations with the statistical correlation fluctuations arising in simulated Gaussian noise data and in LIGO data at times when no event is claimed. Our results for the significance of the observed cross-correlations are broadly consistent with those announced by the LIGO Scientific and Virgo Collaborations based on matched-filter analysis. In the same data, if we subtract the maximum likelihood waveforms corresponding to the announced signals, no residual cross-correlations persists at a statistically significant level.