Discovery of Five Recycled Pulsars in a High Galactic Latitude Survey

Abstract

We present five recycled pulsars discovered during a 21 cm survey of approximately 4150 deg2 between 15 and 30 from the Galactic plane using the Parkes radio telescope. One new pulsar, PSR J15283146, has a 61 ms spin period and a massive white dwarf companion. Like many recycled pulsars with heavy companions, the orbital eccentricity is relatively high (0.0002), consistent with evolutionary models that predict less time for circularization. The four remaining pulsars have short spin periods (3 ms < P < 6 ms); three of these have probable white dwarf binary companions and one (PSR J20101323) is isolated. PSR J16003053 is relatively bright for its dispersion measure of 52.3 pc cm3 and promises good timing precision thanks to an intrinsically narrow feature in its pulse profile, resolvable through coherent dedispersion. In this survey, the recycled pulsar discovery rate was 1 per 4 days of telescope time or 1 per 600 deg2 of sky. The variability of these sources implies that there are more millisecond pulsars that might be found by repeating this survey.