The Green Bank Northern Sky Survey: Discovery of a New Neutron Star-Neutron Star Binary

Abstract

We have surveyed 15,900 deg2of the northern sky for millisecond pulsars at 370 MHz with the Green Bank 140ft telescope. The telescope was driven along lines of constant declination such that a given point on the sky was observed for two minutes. A Fourier transform spectrometer synthesized 512-channel spectra across 40 MHz in each of two polarizations. Total intensity levels were boxcar averaged at intervals of 256μs, quantized to 1 bit, and written to tape. Data were processed with the Cray C90 of the Pittsburgh Supercomputer Center. The flux limit of the survey was 8 mJy for slow pulsars. A further 1500 deg2were observed with 20 MHz bandwidth, yielding 71% the usual sensitivity.Eighty-four slow pulsars were detected, of which six were previously unknown. Three recycled pulsars were detected: the relativistic binary B1534+12; the neutron star-white dwarf binary J1022+1001, discovered nearly simultaneously at Arecibo; and J1518+4904, a previously unknown pulsar with a 41 ms rotation period.