A comparison of methods for the detection of gravitational waves from unknown neutron stars

TL;DR

This paper compares various search methods for detecting unknown neutron stars via gravitational waves, highlighting their relative sensitivities, parameter estimation accuracy, and computational efficiency in a mock data challenge.

Contribution

It provides the first benchmark comparison of current search methods for gravitational waves from unknown neutron stars using a mock data challenge.

Findings

Long duration search method has up to twice the sensitivity of short duration methods.

Absence of second derivative frequency does not reduce search sensitivity for plausible signals.

All methods show stable sensitivity across frequency, derivatives, and noise conditions.

Abstract

Rapidly rotating neutron stars are promising sources of continuous gravitational wave radiation for the LIGO and Virgo interferometers. The majority of neutron stars in our galaxy have not been identified with electromagnetic observations. All-sky searches for isolated neutron stars offer the potential to detect gravitational waves from these unidentified sources. The parameter space of these blind all-sky searches, which also cover a large range of frequencies and frequency derivatives, presents a significant computational challenge. Different methods have been designed to perform these searches within acceptable computational limits. Here we describe the first benchmark in a project to compare the search methods currently available for the detection of unknown isolated neutron stars. We employ a mock data challenge to compare the ability of each search method to recover signals simulated assuming a standard signal model. We find similar performance among the short duration search methods, while the long duration search method achieves up to a factor of two higher sensitivity. We find the absence of second derivative frequency in the search parameter space does not degrade search sensivity for signals with physically plausible second derivative frequencies. We also report on the parameter estimation accuracy of each search method, and the stability of the sensitivity in frequency, frequency derivative and in the presence of detector noise.