Pathfinding pulsar observations with the CVN incorporating the FAST

TL;DR

This paper demonstrates successful pulsar observations using the Chinese VLBI Network combined with FAST, achieving high-precision astrometry that surpasses previous timing methods.

Contribution

It presents the first pathfinding VLBI observations of pulsars with CVN incorporating FAST, improving positional accuracy through phase-referencing and pulsar binning modes.

Findings

Detected pulsars with milliarcsecond positional accuracy

Achieved better agreement with predicted positions than timing observations

Validated VLBI as a precise, model-independent method for pulsar astrometry

Abstract

The importance of Very Long Baseline Interferometry (VLBI) for pulsar research is becoming increasingly prominent and receiving more and more attention. In this paper, we present pathfinding pulsar observation results with the Chinese VLBI Network (CVN) incorporating the Five-hundred-meter Aperture Spherical radio Telescope (FAST). On MJD 60045 (April 11th, 2023), PSRs B0919+06 and B1133+16 were observed with the phase-referencing mode in the L-band using four radio telescopes (FAST, TianMa, Haoping and Nanshan) and correlated with the pulsar binning mode of the distributed FX-style software correlator in Shanghai. After further data processing with the NRAO Astronomical Image Processing System (AIPS), we detected these two pulsars and fitted their current positions with accuracy at the milliarcsecond level. By comparison, our results show significantly better agreement with predicted values based on historical VLBI observations than that with previous timing observations, as pulsar astrometry with the VLBI provides a more direct and model-independent method for accurately obtaining related parameters.