Arecibo and FAST Timing Follow-up of twelve Millisecond Pulsars Discovered in Commensal Radio Astronomy FAST Survey

TL;DR

This paper presents detailed timing, polarization, and orbital data for twelve millisecond pulsars discovered by FAST, revealing their binary characteristics and consistency with MSP-Helium white dwarf system models.

Contribution

It provides the first comprehensive timing and polarization analysis of twelve MSPs discovered with FAST, including orbital and system parameter measurements.

Findings

Eleven pulsars are in neutron star-white dwarf binaries.

Ten systems match theoretical MSP-He WD expectations.

One pulsar shows potential low orbital inclination effects.

Abstract

We report the phase-connected timing ephemeris, polarization pulse profiles, Faraday rotation measurements, and Rotating-Vector-Model (RVM) fitting results of twelve millisecond pulsars (MSPs) discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in the Commensal radio Astronomy FAST survey (CRAFTS). The timing campaigns were carried out with FAST and Arecibo over three years. Eleven of the twelve pulsars are in neutron star - white dwarf binary systems, with orbital periods between 2.4 and 100 d. Ten of them have spin periods, companion masses, and orbital eccentricities that are consistent with the theoretical expectations for MSP - Helium white dwarf (He WD) systems. The last binary pulsar (PSR J1912$-$0952) has a significantly smaller spin frequency and a smaller companion mass, the latter could be caused by a low orbital inclination for the system. Its orbital period of 29 days is well within the range of orbital periods where some MSP - He WD systems have shown anomalous eccentricities, however, the eccentricity of PSR J1912$-$0952 is typical of what one finds for the remaining MSP - He WD systems.