Observations of PSR J1357−6429 at 2.1 GHz with the Australia Telescope Compact Array

PSR J1357−6429 is a young and energetic radio pulsar detected in X-rays and γ-rays. It powers a compact pulsar wind nebula with a jet visible in X-rays and a large-scale plerion detected in X-ray and TeV ranges. Previous multiwavelength studies suggested that the pulsar has a significant proper motion of about 180 mas yr⁻¹, implying an extremely high transverse velocity of about 2000 km s⁻¹. In order to verify this, we performed radio-interferometric observations of PSR J1357−6429 with the Australia Telescope Compact Array (ATCA) in the 2.1-GHz band. We detected the pulsar with a mean flux density of 212 ± 5 μJy and obtained the most accurate pulsar position: RA = 13^h57^m02s.525(14), Dec. =−64°29'29".89(15). Using both new and archival ATCA data, we did not find any proper motion and estimated its 90 per cent upper limit as μ < 106 mas yr⁻¹. The pulsar shows a highly polarized single pulse, as was observed earlier at 1.4 GHz. Spectral analysis revealed a shallow spectral index α_ν = 0.5 ± 0.1. Based on our new radio position of the pulsar, we discount the claim of an optical counterpart candidate reported previously.