The FAST Galactic Plane Pulsar Snapshot Survey – III. Timing results of 30 newly discovered pulsars

Abstract

Timing observations are crucial for determining the basic parameters of newly discovered pulsars. Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) with the L-band 19-beam receiver covering the frequency range of 1.0–1.5 GHz, the FAST Galactic Plane Pulsar Snapshot (GPPS) Survey has discovered more than 600 faint pulsars with flux densities of only a few or a few tens of μJy at 1.25 GHz. To obtain accurate position, spin parameters and dispersion measure of a pulsar, and to calculate derived parameters such as the characteristic age and surface magnetic field, we collect available FAST pulsar data obtained either through targeted follow-up observations or through coincidental survey observations with one of the 19 beams of the receiver. From these data we obtain time of arrival (TOA) measurements for 30 newly discovered pulsars as well as for 13 known pulsars. We demonstrate that the TOA measurements acquired by the FAST from any beams of the receiver in any observation mode (e.g. the tracking mode or the snapshot mode) can be combined to get timing solutions. We update the ephemerides of 13 previously known pulsars and obtain the first phase-coherent timing results for 30 isolated pulsars discovered in the FAST GPPS Survey. Notably, PSR J1904+0853 is an isolated millisecond pulsar, PSR J1906+0757 is a disrupted recycled pulsar, and PSR J1856+0211 has a long period of 9.89 s that can constrain pulsar death lines. Based on these timing solutions, all available FAST data have been added together to obtain the best pulse profiles for these pulsars.

Discovery of Four Pulsars in a Pilot Survey at Intermediate Galactic Latitudes with FAST

“…Currently, the Five-hundred-meter Aperture Spherical Telescope (FAST) is carrying out two major surveys with a focus on radio pulsars, the Commensal Radio Astronomy Fast Survey (CRAFTS; Li et al 2018) and the Galactic Plane Pulsar Survey (GPPS; Han et al 2021). So far, CRAFTS has discovered 179 radio pulsars, including 45 MSPs 15 (Qian et al 2019;Zhang et al 2019;Cameron et al 2020;Cruces et al 2021;Wang et al 2021aWang et al , 2021bTedila et al 2022;Wen et al 2022;Miao et al 2023;Wu et al 2023), and GPPS has discovered 618 radio pulsars, including 148 MSPs 16 (Han et al 2021;Zhou et al 2023;Su et al 2023). While these two surveys complement each other and GPPS is expected to cover Galactic latitudes up to 10°, a large fraction of intermediate Galactic latitudes (10°-15°) that are particularly rich in good-timer MSPs are still not covered with sufficient sensitivity.…”