Ganija, M.Hosken, D.Munch, J.Ottaway, D.Veitch, P.2012-05-112012-05-112012Physical Review D: Particles, Fields, Gravitation and Cosmology, 2012; 85(2):022001-1-022001-191550-79981550-2368http://hdl.handle.net/2440/70839We report on an all-sky search for periodic gravitational waves in the frequency band 50–800 Hz and with the frequency time derivative in the range of 0 through -6×10-9  Hz/s. Such a signal could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. After recent improvements in the search program that yielded a 10× increase in computational efficiency, we have searched in two years of data collected during LIGO’s fifth science run and have obtained the most sensitive all-sky upper limits on gravitational-wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude h0 is 1×10-24, while at the high end of our frequency range we achieve a worst-case upper limit of 3.8×10-24 for all polarizations and sky locations. These results constitute a factor of 2 improvement upon previously published data. A new detection pipeline utilizing a loosely coherent algorithm was able to follow up weaker outliers, increasing the volume of space where signals can be detected by a factor of 10, but has not revealed any gravitational-wave signals. The pipeline has been tested for robustness with respect to deviations from the model of an isolated neutron star, such as caused by a low-mass or long-period binary companion.en© 2012 American Physical SocietyJournal article002011598210.1103/PhysRevD.85.0220010002989897000012-s2.0-8486301176626173Ganija, M. [0000-0002-6882-3930]Ottaway, D. [0000-0001-6794-1591]Veitch, P. [0000-0002-2597-435X]