End-to-end algorithm for hierarchical area searches for long-duration GW sources for GEO 600

Abstract

We describe a hierarchical, highly parallel computer algorithm to perform searches for unknown sources of continuous gravitational waves -- spinning neutron stars in the Galaxy -- over wide areas of the sky and wide frequency bandwidths. We optimize the algorithm for an observing period of 4 months and an available computing power of 20 Gflops, in a search for neutron stars resembling millisecond pulsars. We show that, if we restrict the search to the galactic plane, the method will detect any star whose signal is stronger than 15 times the $1σ$ noise level of a detector over that search period. Since on grounds of confidence the minimum identifiable signal should be about 10 times noise, our algorithm does only 50% worse than this and runs on a computer with achievable processing speed.