Timing and Scintillation Studies of Pulsars in Globular Cluster M3 (NGC 5272) with FAST

TL;DR

This study provides detailed timing solutions for five pulsars in globular cluster M3 using FAST data, revealing their orbital characteristics, scintillation properties, and the nature of their scattering medium, with some solutions obtained for the first time.

Contribution

First-time timing solutions for PSRs M3E and F in M3, analysis of scintillation properties, and insights into the scattering medium's anisotropy using FAST archival data.

Findings

PSRs M3E and F have low-mass companions in circular orbits.

Scintillation timescales range from 7 to 60 minutes.

Scintillation bandwidths indicate strong, anisotropic scintillation.

Abstract

We present the phase-connected timing solutions of all the five pulsars in globular cluster (GC) M3 (NGC 5272), namely PSRs M3A to F (PSRs J1342+2822A to F), with the exception of PSR M3C, from FAST archival data. In these timing solutions, those of PSRs M3E, and F are obtained for the first time. We find that PSRs M3E and F have low mass companions, and are in circular orbits with periods of 7.1 and 3.0 days, respectively. For PSR M3C, we have not detected it in all the 41 observations. We found no X-ray counterparts for these pulsars in archival Chandra images in the band of 0.2-20 keV. We noticed that the pulsars in M3 seem to be native. From the Auto-Correlation Function (ACF) analysis of the M3A's and M3B's dynamic spectra, the scintillation timescale ranges from $7.0\pm0.3$ min to $60.0\pm0.6$ min, and the scintillation bandwidth ranges from $4.6\pm0.2$ MHz to $57.1\pm1.1$ MHz. The measured scintillation bandwidths from the dynamic spectra indicate strong scintillation, and the scattering medium is anisotropic. From the secondary spectra, we captured a scintillation arc only for PSR M3B with a curvature of $649\pm23 {\rm m}^{-1} {\rm mHz}^{-2}$.