Search for Periodic Radio Signals from Double Neutron Star System Companions Using the Fast Folding Algorithm

TL;DR

This study employed the Fast Folding Algorithm and data resampling techniques on FAST telescope data to search for radio signals from potential pulsar companions in double neutron star systems, but no new signals were detected.

Contribution

It is the first application of the Fast Folding Algorithm combined with data resampling to search for long-period pulsars in double neutron star systems using FAST data.

Findings

Improved detection of known pulsars through the method.

No new companion signals found in the data.

Future observations may benefit from geodetic precession effects.

Abstract

As most of the companions in the double neutron star systems should be normal pulsars, the Fast Folding Algorithm (FFA), which is suitable for finding these long spin period pulsars, was used to search their possible radio signals. A time domain resampling code PYSOLATOR was used to maximize the available data length by removing the orbital modulation. We collected and processed 272.2 hours observational data taken by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) for the 13 double neutron star systems in its sky. The signal-to-noise ratios of known pulsar signals are obviously improved by this search method, including the detection of a faint pulsar signal which only saw by folding the data. Unfortunately, no companion signals were found among all the 197962 candidates. Geodetic precession of the orbit could enhance detectability in future observations.