LIGO Detector Characterization in the Second and Third Observing Runs

TL;DR

This paper details the methods and datasets used to characterize LIGO detectors during the second and third observing runs, enhancing gravitational-wave detection sensitivity and supporting broader scientific analysis.

Contribution

It introduces comprehensive characterization methods and curated datasets that facilitate gravitational-wave data analysis and community engagement.

Findings

Increased detector sensitivity in O2 and O3 runs.

Confirmation of all observed gravitational-wave events.

Preparedness for higher alert rates in future runs.

Abstract

The characterization of the Advanced LIGO detectors in the second and third observing runs has increased the sensitivity of the instruments, allowing for a higher number of detectable gravitational-wave signals, and provided confirmation of all observed gravitational-wave events. In this work, we present the methods used to characterize the LIGO detectors and curate the publicly available datasets, including the LIGO strain data and data quality products. We describe the essential role of these datasets in LIGO-Virgo Collaboration analyses of gravitational-waves from both transient and persistent sources and include details on the provenance of these datasets in order to support analyses of LIGO data by the broader community. Finally, we explain anticipated changes in the role of detector characterization and current efforts to prepare for the high rate of gravitational-wave alerts and events in future observing runs.