Detection and characterization of instrumental transients in LISA Pathfinder and their projection to LISA

TL;DR

This paper analyzes transient signals in LISA Pathfinder data, characterizes their features, and assesses their potential impact on future LISA gravitational-wave observations, providing tools for mitigation.

Contribution

It offers the first comprehensive catalog of LPF transient events, a phenomenological model for glitches, and a synthetic glitch generator for LISA data analysis.

Findings

Identified and characterized LPF transient events.

Developed a phenomenological shapelet model for glitches.

Created a synthetic glitch generator for future LISA studies.

Abstract

The LISA Pathfinder (LPF) mission succeeded outstandingly in demonstrating key technological aspects of future space-borne gravitational-wave detectors, such as the Laser Interferometer Space Antenna (LISA). Specifically, LPF demonstrated with unprecedented sensitivity the measurement of the relative acceleration of two free-falling cubic test masses. Although most disruptive non-gravitational forces have been identified and their effects mitigated through a series of calibration processes, some faint transient signals of yet unexplained origin remain in the measurements. If they appear in the LISA data, these perturbations (also called glitches) could skew the characterization of gravitational-wave sources or even be confused with gravitational-wave bursts. For the first time, we provide a comprehensive census of LPF transient events. Our analysis is based on a phenomenological shapelet model allowing us to derive simple statistics about the physical features of the glitch population. We then implement a generator of synthetic glitches designed to be used for subsequent LISA studies, and perform a preliminary evaluation of the effect of the glitches on future LISA data analyses.