PALFA Single-Pulse Pipeline: New Pulsars, Rotating Radio Transients and a Candidate Fast Radio Burst.

We present a new single-pulse pipeline for the PALFA survey to efficiently identify single radio pulses from pulsars, rotating radio transients (RRATs), and fast radio bursts (FRBs). We conducted a sensitivity analysis of this new pipeline in which many single pulses were injected into PALFA data and run through the pipeline. We find that for single pulse widths <5 ms, the sensitivity of our new pipeline is at most a factor of similar to 2 less sensitive than theoretically predicted. For pulse widths >10 ms, as the DM decreases, the degradation in sensitivity gets worse and can increase up to a factor of similar to 4.5. Using this pipeline, we have discovered seven pulsars and two RRATs, and identified three candidate RRATs and one candidate FRB. The confirmed pulsars and RRATs have DMs ranging from 133 to 386 pc cm(-3) and flux densities ranging from 20 to 160 mJy. The pulsar periods range from 0.4 to 2.1 s. We report on candidate FRB 141113, which is likely astrophysical and extragalactic, having DM similar or equal to 400 pc cm(-3), which is over the Galactic maximum along this line of sight by similar to 100-200 pc cm(-3). We consider implications for the FRB population and show via simulations that if FRB 141113 is real and extragalactic, the slope a of the distribution of integral source counts as a function of flux density (N(>S) alpha S-alpha) is 1.4 +/- 0.5 (95% confidence range). However, this conclusion is dependent on assumptions that require verification.