The High Time Resolution Universe Pulsar Survey-XIX. A coherent GPU accelerated reprocessing and the discovery of 71 pulsars in the Southern Galactic plane

TL;DR

This paper presents a GPU-accelerated reprocessing of the HTRU-S LowLat pulsar survey data, leading to the discovery of 71 new pulsars, including millisecond and high-DM pulsars, by employing advanced coherent search techniques.

Contribution

The study introduces a GPU-accelerated, coherent reprocessing pipeline that enhances pulsar detection sensitivity and discovers new pulsars missed by previous analyses.

Findings

Discovered 71 new pulsars, including 6 MSPs and 7 high-DM pulsars.

Achieved survey detection goals and identified reasons for previous missed pulsars.

Demonstrated the effectiveness of coherent folding and candidate classification techniques.

Abstract

We have conducted a GPU accelerated reprocessing of $\sim 87\%$ of the archival data from the High Time Resolution Universe South Low Latitude (HTRU-S LowLat) pulsar survey by implementing a pulsar search pipeline that was previously used to reprocess the Parkes Multibeam pulsar survey (PMPS). We coherently searched the full 72-min observations of the survey with an acceleration search range up to $|50|\, \rm m\,s^{-2}$, which is most sensitive to binary pulsars experiencing nearly constant acceleration during 72 minutes of their orbital period. Here we report the discovery of 71 pulsars, including 6 millisecond pulsars (MSPs) of which five are in binary systems, and seven pulsars with very high dispersion measures (DM $>800 \, \rm pc \, cm^{-3}$). These pulsar discoveries largely arose by folding candidates to a much lower spectral signal-to-noise ratio than previous surveys, and exploiting the coherence of folding over the incoherent summing of the Fourier components to discover new pulsars as well as candidate classification techniques. We show that these pulsars could be fainter and on average more distant as compared to both the previously reported 100 HTRU-S LowLat pulsars and background pulsar population in the survey region. We have assessed the effectiveness of our search method and the overall pulsar yield of the survey. We show that through this reprocessing we have achieved the expected survey goals including the predicted number of pulsars in the survey region and discuss the major causes as to why these pulsars were missed in previous processings of the survey.