Eccentric Binary Neutron Star Search Prospects for Cosmic Explorer

TL;DR

This paper evaluates Cosmic Explorer's capability to detect and measure eccentric binary neutron star systems, demonstrating effective search strategies for various eccentricities with manageable computational costs.

Contribution

It introduces template bank construction methods for eccentric binaries and assesses Cosmic Explorer's ability to distinguish eccentricity levels.

Findings

Template banks effective for eccentricities up to 0.05

Detection cost similar to Advanced LIGO

Cosmic Explorer can distinguish small eccentricities at high confidence

Abstract

We determine the ability of Cosmic Explorer, a proposed third-generation gravitational-wave observatory, to detect eccentric binary neutron stars and to measure their eccentricity. We find that for a matched-filter search, template banks constructed using binaries in quasi-circular orbits are effectual for eccentric neutron star binaries with $e_{7} \leq 0.004$ ($e_{7} \leq 0.003$) for CE1 (CE2), where $e_7$ is the binary's eccentricity at a gravitational-wave frequency of 7~Hz. We show that stochastic template placement can be used to construct a matched-filter search for binaries with larger eccentricities and construct an effectual template bank for binaries with $e_{7} \leq 0.05$. We show that the computational cost of both the search for binaries in quasi-circular orbits and eccentric orbits is not significantly larger for Cosmic Explorer than for Advanced LIGO and is accessible with present-day computational resources. We investigate Cosmic Explorer's ability to distinguish between circular and eccentric binaries. We estimate that for a binary with a signal-to-noise ratio of 8 (800), Cosmic Explorer can distinguish between a circular binary and a binary with eccentricity $e_7 \gtrsim 10^{-2}$ ($10^{-3}$) at 90% confidence.