First Coincidence Search among Periodic Gravitational Wave Source Candidates Using Virgo Data

This paper describes the ongoing work we are doing on the blind search for continuous gravitational waves emitted by isolated asymmetric rotating neutron stars in the data of the interferometric detector Virgo. An optimal blind search for continuous sources cannot be done with the presently available computing power. We have developed a hierarchical procedure which strongly cut the computational needs, with respect to the optimal analysis, at the cost of a small reduction in sensitivity.1 We have used the data of the two commissioning runs C6 and C7 to build two periodic source candidate data bases. Each candidate is defined by the physical parameters of the source, namely frequency, sky position and value of the spin-down first order parameter. We have performed an all sky analysis, covering the frequency band 50 - 1050 Hz and spin-down in 0 - 1.52 · 10-4 Hz/day. We have done a preliminary search for coincidences between the physical parameters of the two candidate sets. We present the full procedure and the results.