Environmental Noise in Advanced LIGO Detectors

TL;DR

This paper discusses how environmental noise affects Advanced LIGO detectors, detailing methods for monitoring, mitigating noise sources, and ensuring the reliability of gravitational wave detections across multiple observing runs.

Contribution

It introduces improved techniques for environmental noise monitoring and mitigation, enhancing the sensitivity and validation processes of gravitational wave observations in Advanced LIGO.

Findings

Environmental noise levels are kept below background noise.

Methods have successfully identified and mitigated noise sources.

Environmental monitoring supports validation of gravitational wave events.

Abstract

The sensitivity of the Advanced LIGO detectors to gravitational waves can be affected by environmental disturbances external to the detectors themselves. Since the transition from the former initial LIGO phase, many improvements have been made to the equipment and techniques used to investigate these environmental effects. These methods have aided in tracking down and mitigating noise sources throughout the first three observing runs of the advanced detector era, keeping the ambient contribution of environmental noise below the background noise levels of the detectors. In this paper we describe the methods used and how they have led to the mitigation of noise sources, the role that environmental monitoring has played in the validation of gravitational wave events, and plans for future observing runs.