Instrumental vetoes for transient gravitational-wave triggers using noise-coupling models: The bilinear-coupling veto

Abstract

The Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo recently completed searches for gravitational waves at their initial target sensitivities, and soon Advanced LIGO and Advanced Virgo will commence observations with even better capabilities. In the search for short-duration signals, such as coalescing compact binary inspirals or “burst” events, noise transients can be problematic. Interferometric gravitational-wave detectors are highly complex instruments, and, based on the experience from the past, the data often contain a large number of noise transients that are not easily distinguishable from possible gravitational-wave signals. In order to perform a sensitive search for short-duration gravitational-wave signals it is important to identify these noise artifacts, and to “veto” them. Here we describe such a veto, the bilinear-coupling veto, that makes use of an empirical model of the coupling of instrumental noise to the output strain channel of the interferometric gravitational-wave detector. In this method, we check whether the data from the output strain channel at the time of an apparent signal is consistent with the data from a bilinear combination of auxiliary channels. We discuss the results of the application of this veto to recent LIGO data, and its possible utility when used with data from Advanced LIGO and Advanced Virgo.