VLBI astrometry on the white dwarf pulsar AR Scorpii
Journal article, 2023

AR Scorpii (AR Sco), the only-known radio-pulsing white dwarf binary, shows unusual pulsating emission at the radio, infrared, optical, and ultraviolet bands. To determine its astrometric parameters at the radio band independently, we conducted multi-epoch Very Long Baseline Interferometry (VLBI) phase-referencing observations with the European VLBI Network at 5 GHz and the Chinese VLBI Network plus the Warkworth 30-m telescope (New Zealand) at 8.6 GHz. By using the differential VLBI astrometry, we provide high-precision astrometric measurements on the parallax (pi = 8.52(-0.07)(+0.04) mas) and proper motion (mu(alpha) = 9.48(-0.07)(+0.04) mas yr(-1), mu(delta) = -51.32(-0.38)(+0.22) mas yr (-1)). The new VLBI results agree with the optical Gaia astrometry. Our kinematic analysis reveals that the Galactic space velocities of AR Sco are quite consistent with that of both intermediate polars and polars. Combined with the previous tightest VLBI constraint on the size, our parallax distance suggests that the radio emission of AR Sco should be located within the light cylinder of its white dwarf.

white dwarfs

pulsars: individual: AR Sco

radio continuum: stars

techniques: high angular resolution

parallaxes

Author

Pengfei Jiang

Chinese Academy of Sciences

Lang Cui

Chinese Academy of Sciences

Jun Yang

Chalmers, Space, Earth and Environment, Onsala Space Observatory

Bo Zhang

Chinese Academy of Sciences

Shuangjing Xu

Chinese Academy of Sciences

Korea Astronomy and Space Science Institute

Fengchun Shu

Chinese Academy of Sciences

Wu Jiang

Chinese Academy of Sciences

Wen Chen

Chinese Academy of Sciences

Guanghui Li

Chinese Academy of Sciences

Bo Xia

Chinese Academy of Sciences

Stuart Weston

Auckland University of Technology

Sergei Gulyaev

Auckland University of Technology

Hongmin Cao

Shangqiu Normal University

Xiang Liu

Chinese Academy of Sciences

Tao An

Chinese Academy of Sciences

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 520 2 2942-2951

Novel EXplorations Pushing Robust e-VLBI Services (NEXPReS)

European Commission (EC) (EC/FP7/261525), 2010-07-01 -- 2013-06-30.

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Other Physics Topics

DOI

10.1093/mnras/stad327

More information

Latest update

9/7/2023 1