Data collected by the GEO 600 and LIGO interferometric gravitational wave detectors during their first observational science run were searched for continuous gravitational waves from the pulsar J1939+2134 at twice its rotation frequency. Two independent analysis methods were used and are demonstrated in this paper: a frequency domain method and a time domain method. Both achieve consistent null results, placing new upper limits on the strength of the pulsar’s gravitational wave emission. A model emission mechanism is used to interpret the limits as a constraint on the pulsar’s equatorial ellipticity.
Abbott, B., et al. “Setting Upper Limits on the Strength of Periodic Gravitational Waves from PSR J1939+2134 Using the First Science Data from the GEO 600 and LIGO Detectors.” Physical Review D, vol. 69, no. 8, American Physical Society, Apr. 2004, p. 082004, doi:10.1103/PhysRevD.69.082004.
Physical Review D