A Pilot Study of Mildly Recycled Pulsars: A Case Study of PSR J2338+4818

TL;DR

This pilot study of PSR J2338+4818, a mildly recycled pulsar discovered with FAST, provides detailed timing, single pulse, and scintillation analyses, offering insights into its formation and properties.

Contribution

The study offers the first detailed timing and pulse analysis of PSR J2338+4818, including single pulse and scintillation properties, advancing understanding of mildly recycled pulsars.

Findings

Detected 27,228 single pulses with S/N > 7.

No evidence of pulse nulling was found in observations.

Interstellar scintillation timescales ranged from 2.93 to 25.26 minutes.

Abstract

Mildly recycled pulsars are neutron stars partially spun up through relatively short mass-transfer phases, typically with massive carbon-oxygen (CO) or oxygen-neon-magnesium (ONeMg) white dwarf companions. PSR J2338+4818, a mildly recycled pulsar, was discovered with the Five-hundred-meter Aperture Spherical Telescope (FAST). As a pilot study on the formation and evolutionary pathways of mildly recycled pulsars, we present the updated timing solution for PSR J2338+4818 and examine its single pulses and scintillation properties. Aided by the sensitivity of FAST, the single pulses of PSR J2338+4818 were systematically studied. 27,228 single pulses with S/N > 7 have been detected in our observations. For the FAST ultra-wideband observation on MJD 61045, the receiver was still in the technical commissioning phase, and then only a preliminary single-pulse search was performed. Pulse nulling was examined using a Markov Chain Monte Carlo (MCMC) method, but no evidence for nulling was found. The possible long-term nulling reported by previous studies did not occur in any of our observations in either the 1.0 to 1.5 GHz band or the 300 to 600 MHz band. Interstellar scintillation is evident in our observations. The measured scintillation timescales and bandwidths range from 2.93 to 25.26 minutes and 1.68 to 27.41 MHz, respectively. In all observations, no clear scintillation arc was found in the secondary spectra of PSR J2338+4818.