Arecibo Timing and Single-Pulse Observations of Eighteen Pulsars

We present new results of timing and single-pulse measurements for 18 radio pulsars discovered in 1993-1997 by the Penn State/Naval Research Laboratory declination-strip survey conducted with the 305 m Arecibo Telescope at 430 MHz. Long-term timing measurements have led to significant improvements of the rotational and the astrometric parameters of these sources, including the millisecond pulsar, PSR J1709+2313, and the pulsar located within the supernova remnant S147, PSR J0538+2817. Single-pulse studies of the brightest objects in the sample have revealed an unusual "bursting" pulsar, PSR J1752+2359, two new drifting subpulse pulsars, PSR J1649+2533 and PSR J2155+2813, and another example of a pulsar with profile mode changes, PSR J1746+2540. PSR J1752+2359 is characterized by bursts of emission, which appear once every 3-5 minutes and decay exponentially on a ~45 s timescale. PSR J1649+2533 spends ~30% of the time in a null state with no detectable radio emission.