The FAST Galactic Plane Pulsar Snapshot survey: I. Project design and pulsar discoveries ^⋆

Abstract

Discovery of pulsars is one of the main goals for large radio telescopes. The Five-hundred-meter Aperture Spherical radio Telescope (FAST), that incorporates an L-band 19-beam receiver with a system temperature of about 20 K, is the most sensitive radio telescope utilized for discovering pulsars. We designed the snapshot observation mode for a FAST key science project, the Galactic Plane Pulsar Snapshot (GPPS) survey, in which every four nearby pointings can observe a cover of a sky patch of 0.1575 square degrees through beam-switching of the L-band 19-beam receiver. The integration time for each pointing is 300 seconds so that the GPPS observations for a cover can be made in 21 minutes. The goal of the GPPS survey is to discover pulsars within the Galactic latitude of ± 10° from the Galactic plane, and the highest priority is given to the inner Galaxy within ± 5°. Up to now, the GPPS survey has discovered 201 pulsars, including currently the faintest pulsars which cannot be detected by other telescopes, pulsars with extremely high dispersion measures (DMs) which challenge the currently widely used models for the Galactic electron density distribution, pulsars coincident with supernova remnants, 40 millisecond pulsars, 16 binary pulsars, some nulling and mode-changing pulsars and rotating radio transients (RRATs). The follow-up observations for confirmation of new pulsars have polarization-signals recorded for polarization profiles of the pulsars. Re-detection of previously known pulsars in the survey data also leads to significant improvements in parameters for 64 pulsars. The GPPS survey discoveries are published and will be updated at http://zmtt.bao.ac.cn/GPPS/.

Long-period Pulsars as Possible Outcomes of Supernova Fallback Accretion

“…On the other hand, in systems where the initial magnetic fields are lower (∼ 10 12−13 G), fallback disk accretion (even if present) is expected to have a negligible effect on the spinperiod evolution on the timescales of ∼ 10 4 yr. The major-ity of neutron stars will therefore primarily undergo standard dipolar electromagnetic spin-down and recover rotation periods below ∼ 12 s. In our framework, we therefore naturally recover the pulsar population which is observed to spin in the range ∼ 0.002-12 s. Note that the recently discovered radio pulsars PSR J1903+0433 (Han et al 2021) and PSR J0250+5854 (Tan et al 2018) with periods of 14 s and 23 s, respectively, could be easily accommodated within our fallback accretion scenario. However, both sources can in principle also be explained within the standard evolutionary scenario provided that crustal field decay is very weak (essentially requiring the absence of a highly resistive pasta layer; see Pons et al 2013) and/or a strong core magnetic field is present.…”

“…Two radio pulsars, PSR J1903+0433 (Han et al 2021) and PSR J0250+5854 (Tan et al 2018), have been recently discovered with periods of 14 s and 23 s, respectively. Moreover, a peculiar radio transient with a periodicity of ∼ 1091 s (GLEAM-X J162759.…”

Search for the correlations between host properties and ${\rm DM_{host}}$ of fast radio bursts: constraints on the baryon mass fraction in IGM

“…With more Galactic plane pulsars discovered by e.g. the FAST telescope [94], DM MW,ISM at low latitude is expected to be modeled more accurately in the future. In addition, FRB source may also contribute a non negligible DM value, thus introduces additional uncertainty.…”

Insights into the Milky Way pulsar--black hole population using radio and gravitational wave observations

“…While the single dish configuration of FAST gives it the best sensitivity of the three new surveys, MeerKAT's access to most of the Galactic plane (given its location in the Southern hemisphere) as well as a larger field of view than FAST results in it having a higher probability of detecting more than one PSR-BH system. Both of these radio telescopes have initiated surveys of the Galaxy to search for new binary pulsars (Han et al 2021;Sanidas et al 2018) and provide the best opportunity to detect any PSR-BH system that might have been too faint for the current radio telescopes and surveys. In Fig.…”