Einstein@Home search for periodic gravitational waves in early S5 LIGO data

TL;DR

This paper describes a large-scale all-sky search for periodic gravitational waves using LIGO data, leveraging distributed computing to improve sensitivity, but finds no significant signals.

Contribution

It extends Einstein@Home's previous search to three times better sensitivity using 840 hours of LIGO S5 data and distributed computing.

Findings

No significant gravitational wave signals detected.

Over 90% of sources above 3e-24 strain in 125-225 Hz band would have been detected.

Enhanced sensitivity compared to previous LIGO S4 search.

Abstract

This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly-spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The data was searched for quasi-monochromatic waves with frequencies f in the range from 50 Hz to 1500 Hz, with a linear frequency drift \dot{f} (measured at the solar system barycenter) in the range -f/\tau < \dot{f} < 0.1 f/\tau, for a minimum spin-down age \tau of 1000 years for signals below 400 Hz and 8000 years above 400 Hz. The main computational work of the search was distributed over approximately 100000 computers volunteered by the general public. This large computing power allowed the use of a relatively long coherent integration time of 30 hours while searching a large parameter space. This search extends Einstein@Home's previous search in LIGO S4 data to about three times better sensitivity. No statistically significant signals were found. In the 125 Hz to 225 Hz band, more than 90% of sources with dimensionless gravitational-wave strain tensor amplitude greater than 3e-24 would have been detected.