THE ARECIBO 430 MHz INTERMEDIATE GALACTIC LATITUDE SURVEY: DISCOVERY OF NINE RADIO PULSARS

摘要

We have used the Arecibo Radio Telescope to search for millisecond pulsars in two intermediate Galactic latitude regions (7° < |b| < 20°) 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 deg~2, 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 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 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.