The Green Bank Northern Sky Survey for Fast Pulsars

Abstract

We have carried out a survey of the northern sky for millisecond pulsars using the Green Bank 140 foot (43 m) telescope at 370 MHz. Our goal was to find the strongest millisecond pulsars in the northern hemisphere. The flux-density limit of our survey was 8 mJy for slow pulsars with typical pulse shapes and high Galactic latitudes. Spectra were sampled at intervals of 256 μs, so pulsars with periods as short as 512 μs were potentially detectable. We obtained high-quality data covering 15,900 deg2 of sky, or 77% of the northern hemisphere. We observed a further 1500 deg2 with somewhat reduced sensitivity. We detected a total of 84 pulsars, including eight not previously known. The new objects include two recycled pulsars: PSR J1022+1001, a 16.5 ms pulsar in a nearly circular 7.8 day orbit with a white dwarf companion, and PSR J1518+4904, a 40.9 ms pulsar in a mildly relativistic 8.6 day orbit of eccentricity 0.249. We have made timing observations of all the new pulsars, and we summarize their rotation and astrometric parameters. Finally, we compare the full list of detected pulsars with a list of those which should have been detectable according to their published flux densities and the characteristics of our search.