F-statistic search for white-dwarf binaries in the first Mock LISA Data Challenge

TL;DR

This paper applies the F-statistic detection method, originally for ground-based detectors, to LISA data, successfully identifying white-dwarf binary signals in the Mock LISA Data Challenge using the long-wavelength limit.

Contribution

It demonstrates the effectiveness of the F-statistic in LISA data analysis and shows that the long-wavelength limit suffices for detection and localization of signals.

Findings

LWL is sufficient for detection at high frequencies

Accurate TDI modeling is mainly needed for amplitude estimation

Successful identification of white-dwarf binaries in mock data

Abstract

The F-statistic is an optimal detection statistic for continuous gravitational waves, i.e., long-duration (quasi-)monochromatic signals with slowly-varying intrinsic frequency. This method was originally developed in the context of ground-based detectors, but it is equally applicable to LISA where many signals fall into this class of signals. We report on the application of a LIGO/GEO F-statistic code to LISA data-analysis using the long-wavelength limit (LWL), and we present results of our search for white-dwarf binary signals in the first Mock LISA Data Challenge. Somewhat surprisingly, the LWL is found to be sufficient -- even at high frequencies -- for detection of signals and their accurate localization on the sky and in frequency, while a more accurate modelling of the TDI response only seems necessary to correctly estimate the four amplitude parameters.