Have any LISA verification binaries been found?

TL;DR

This paper evaluates whether known electromagnetic ultra-compact binaries, called verification binaries, can reliably serve as gravitational wave sources for LISA, considering the complex galactic foreground and analysis ambiguities.

Contribution

It provides a quantitative analysis showing that current known binaries may not be optimal for LISA data verification due to foreground modeling challenges.

Findings

Analysis of known LISA binaries shows susceptibility to biases without global foreground fitting

Electromagnetically observed binaries are valuable but may not be ideal for LISA data characterization

Global treatment of the galactic foreground is necessary for accurate gravitational wave analysis

Abstract

Some electromagnetically observed ultra-compact binaries will be strong gravitational wave sources for space-based detectors like the Laser Interferometer Space Antenna (LISA). These sources have historically been referred to as "verification binaries" under the assumption that they will be exploited to assess mission performance. This paper quantitatively interrogates that scenario by considering targeted analyses of known galactic sources in the context of a full simulation of the galactic gravitational wave foreground. We find that the analysis of the best currently known LISA binaries, even making maximal use of the available information about the sources, is susceptible to ambiguity or biases when not simultaneously fitting to the rest of the galactic population. While galactic binaries discovered electromagnetically in advance of, or during, the LISA survey are highly valuable multimessenger systems, the need for a global treatment of the galactic gravitational wave foreground calls into question whether or not they are the best sources for data characterization.