VLBI astrometry on the white dwarf pulsar ARScorpii
VLBI astrometry on the white dwarf pulsar ARScorpii
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白矮星脉冲星 ARScorpii 的 VLBI 天体测量
DOI：
10.1093/mnras/stad327
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发表时间：
--
影响因子：
4.8
通讯作者：
Tao An
中科院分区：
文献类型：
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作者：
Pengfei Jiang;Lang Cui;Jun Yang;Bo Zhang;Shuangjing Xu;Fengchun Shu;Wu Jiang;Wen Chen;Guanghui Li;Bo Xia;Stuart Weston;Sergei Gulyaev;Hongmin Cao;Xiang Liu;Tao An
抽象的。 AR天蝎座（AR Sco）是唯一已知的射电脉冲白矮星双星，在射电、红外、光学和紫外波段显示出不寻常的脉动发射。为了独立确定其在射电频段的天体测量参数，我们利用欧洲VLBI网络（EVN）在5GHz和中国VLBI网络（CVN）加上瓦克沃斯30米望远镜（新西兰）在8.6GHz进行了多历元甚长基线干涉测量（VLBI）相位参考观测。通过使用差分VLBI天体测量，我们提供了视差（$pi =8.52_{-0.07}^{+0.04}$mas）和自行（$mu _{alpha }=9.48_{-0.07}^{+0.04}$masyr−1, $mu _{delta）的高精度天体测量}=-51.32_{-0.38}^{+0.22}$masyr−1)。新的 VLBI 结果与光学盖亚天体测量一致。我们的运动学分析表明，AR Sco 的银河空间速度与中间极点（IP）和极点的银河空间速度非常一致。结合之前最严格的 VLBI 对尺寸的限制，我们的视差距离表明 ARSco 的射电发射应该位于其白矮星的光柱内。
Abstract. 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 (EVN) at 5GHz and the Chinese VLBI Network (CVN) plus the Warkworth 30-metre telescope (New Zealand) at 8.6GHz. 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 ($mu _{alpha }=9.48_{-0.07}^{+0.04}$masyr−1, $mu _{delta }=-51.32_{-0.38}^{+0.22}$masyr−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 (IPs) and polars. Combined with the previous tightest VLBI constraint on the size, our parallax distance suggests that the radio emission of ARSco should be located within the light cylinder of its white dwarf.