The Arecibo 430-MHz Intermediate Galactic Latitude Survey: Discovery of Nine Radio Pulsars

Abstract

We have used the Arecibo Radio Telescope to search for millisecond pulsars in two intermediate Galactic latitude regions (7 deg < | b | < 20 deg) accessible to this telescope. For these latitudes the useful millisecond pulsar search volume achieved by Arecibo's 430-MHz beam is predicted to be maximal. Searching a total of 130 square degrees, we have discovered nine new pulsars and detected four previously known objects. We compare the results of this survey with those of other 430-MHz surveys carried out at Arecibo and of an intermediate latitude survey made at Parkes that included part of our search area; the latter independently found two of the nine pulsars we have discovered. At least six of our discoveries are isolated pulsars with ages between 5 and 300 Myr; one of these, PSR J1819+1305, exhibits very marked and periodic nulling. We have also found a recycled pulsar, PSR J2016+1948. With a rotational period of 65 ms, this is a member of a binary system with a 635-day orbital period. We discuss some of the the properties of this system in detail, and indicate its potential to provide a test of the Strong Equivalence Principle. This pulsar and PSR J0407+16, a similar system now being timed at Arecibo, are by far the best systems known for such a test.