The Galactic Gravitational wave foreground

TL;DR

This paper reviews the Galactic binary populations that form the gravitational wave foreground for LISA, discusses detection prospects, and explores astrophysical insights from combined gravitational and electromagnetic observations.

Contribution

It provides an updated overview of known and expected Galactic binaries relevant for LISA, correcting previous estimates and emphasizing multi-messenger approaches.

Findings

Several hundred systems detectable by LISA.

Updated estimates of optical counterparts.

Enhanced understanding of Galactic binary populations.

Abstract

I present an overview of the Galactic binaries that form the foreground for the ESA/NASA Laser Interferometer Space Antenna (LISA). The currently known population is discussed, as well as current and near-future large-scale surveys that will find new systems. The astrophysics that can be done when the LISA data becomes available is presented, with particular attention to verification binaries, the overall Galactic populations, neutron star and black hole binaries and sources in globular clusters. I discuss the synergy with electro-magnetic observations and correct an error in the estimate of the number of LISA systems that can be found in the optical compared to Nelemans (2006a) and conclude that at least several hundreds of systems should be detectable.