Event rate estimates for LISA extreme mass ratio capture sources

TL;DR

This paper estimates the detection rates of extreme mass ratio inspiral events for LISA, showing it could detect over a thousand such events up to redshift z=1 with realistic data analysis methods.

Contribution

It introduces a first cut data analysis scheme for LISA EMRI detection and estimates the expected number of observable inspiral events.

Findings

LISA can detect EMRIs out to redshift z=1.

Over a thousand EMRI events could be detected during LISA's mission.

Detection thresholds depend on signal-to-noise ratio estimates.

Abstract

One of the most exciting prospects for the LISA gravitational wave observatory is the detection of gravitational radiation from the inspiral of a compact object into a supermassive black hole. The large inspiral parameter space and low amplitude of the signal makes detection of these sources computationally challenging. We outline here a first cut data analysis scheme that assumes realistic computational resources. In the context of this scheme, we estimate the signal-to-noise ratio that a source requires to pass our thresholds and be detected. Combining this with an estimate of the population of sources in the Universe, we estimate the number of inspiral events that LISA could detect. The preliminary results are very encouraging -- with the baseline design, LISA can see inspirals out to a redshift z=1 and should detect over a thousand events during the mission lifetime.