Archival searches for stellar-mass binary black holes in LISA

TL;DR

This paper discusses how high-precision measurements from future ground-based gravitational-wave detectors can assist in identifying stellar-mass binary black hole signals in LISA data, despite their low individual detectability.

Contribution

It introduces a method leveraging ground-based detector data to improve archival searches for binary black holes in LISA observations.

Findings

Ground-based detectors will measure binary black holes with high signal-to-noise ratios.

Archival searches can recover tens of signals annually using ground-based data.

Ground-based measurements enable detection of otherwise undetectable LISA signals.

Abstract

Stellar-mass binary black holes will sweep through the frequency band of the Laser Interferometer Space Antenna (LISA) for months to years before appearing in the audio-band of ground-based gravitational-wave detectors. One can expect several tens of these events up to a distance of $500 \,\mathrm{Mpc}$ each year. The LISA signal-to-noise ratio for such sources even at these close distances will be too small for a blind search to confidently detect them. However, next generation ground-based gravitational-wave detectors, expected to be operational at the time of LISA, will observe them with signal-to-noise ratios of several thousands and measure their parameters very accurately. We show that such high fidelity observations of these sources by ground-based detectors help in archival searches to dig tens of signals out of LISA data each year.