FAST discovery of an extremely radio-faint millisecond pulsar from the Fermi-LAT unassociated source 3FGL J0318.1+0252
Abstract
High sensitivity radio searches of unassociated γ-ray sources have proven to be an effective way of finding new pulsars. Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) during its commissioning phase, we have carried out a number of targeted deep searches of Fermi Large Area Telescope (LAT) γ-ray sources. On February 27, 2018 we discovered an isolated millisecond pulsar (MSP), PSR J0318+0253, coincident with the unassociated γ-ray source 3FGL J0318.1+0252. PSR J0318+0253 has a spin period of 5.19 ms, a dispersion measure (DM) of 26 pc cm‑3 corresponding to a DM distance of about 1.3 kpc, and a period-averaged flux density of (∼11±2) µJy at L-band (1.05–1.45 GHz). Among all high energy MSPs, PSR J0318+0253 is the faintest ever detected in radio bands, by a factor of at least ∼4 in terms of L-band fluxes. With the aid of the radio ephemeris, an analysis of 9.6 years of Fermi-LAT data revealed that PSR J0318+0253 also displays strong γ-ray pulsations. Follow-up observations carried out by both Arecibo and FAST suggest a likely spectral turn-over around 350 MHz. This is the first result from the collaboration between FAST and the Fermi-LAT teams as well as the first confirmed new MSP discovery by FAST, raising hopes for the detection of many more MSPs. Such discoveries will make a significant contribution to our understanding of the neutron star zoo while potentially contributing to the future detection of gravitational waves, via pulsar timing array (PTA) experiments.
- Publication:
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Science China Physics, Mechanics, and Astronomy
- Pub Date:
- December 2021
- DOI:
- 10.1007/s11433-021-1757-5
- arXiv:
- arXiv:2109.00715
- Bibcode:
- 2021SCPMA..6429562W
- Keywords:
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- FAST;
- pulsar;
- radio;
- gamma rays;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 2 figures, 1 table