论文标题
16个脉冲星的新定时测量结果
New timing measurement results of 16 pulsars
论文作者
论文摘要
PULSAR的位置，适当的运动和视差是定时方程中的重要参数。通过脉冲星时间安排准确地拟合天文参数是一项非常具有挑战性的工作，尤其是对于显示不规则正时特性的脉冲星。作为相关技术的快速开发，可以在模型$ \ textrm { - } $独立的模型中测量越来越多的脉冲星的天体参数，并具有非常长的基线干涉法（VLBI）。在这项工作中，我们选择了16个正常的脉冲星，它们的视差和适当的运动尚未成功地拟合时间观察，也没有与相应的最新VLBI解决方案显示出明显的差异，并对其定时属性进行了进一步的研究。在使用最新的VLBI测量值更新Pulsar serphemerides中的星形参数之后，我们通过S and c $ \ textrm { - } $ band从上海Tian MA MA Radio Radio TeleScope（TMRT）获得了这些脉冲星的最新旋转解决方案。与从以前的旋转解决方案中推断出的自旋频率$ν$相比，新的$ \ textrm { - } $ fitted $ν$显示出大于10 $^{ - 9} $ Hz的差异。可以正确删除Shklovsky效应对周期衍生物$ \ dot {p} $的贡献，即通过VLBI Astrometry测得的准确的正确运动和目标脉冲星的优势。这进一步导致了内在特征年龄$τ_ {\ rm c} $的精确估计。新近$ \ textrm { - } $测量的$τ_ {\ rm c} $与相应的先前结果之间的差异为某些脉冲星的2％。 VLBI天文参数解决方案还可以更好地测量时间不规则。对于PSR B0154 $+$ 61，用先前的ephemeris测量的小故障时期（MJD 58279.5）比使用VLBI Astrometrotor参数解决方案获得的结果（MJD 58266.4）晚约13 d。
Pulsar's position, proper motion and parallax are important parameters in timing equations. It is a really challenging work to fit astrometric parameters accurately through pulsar timing, especially for pulsars that show irregular timing properties. As the fast development of related techniques, it is possible to measure astrometric parameters of more and more pulsars in a model$\textrm{-}$independent manner with the Very Long Baseline Interferometry (VLBI). In this work, we select 16 normal pulsars, whose parallax and proper motion have not been successfully fitted with timing observations or show obvious differences with corresponding latest VLBI solutions, and do further studies on their timing properties. After updating astrometric parameters in pulsar ephemerides with the latest VLBI measurements, we derive the latest rotation solutions of these pulsars with observation data at S and C$\textrm{-}$band obtained from the Shanghai Tian Ma Radio Telescope (TMRT). Compared with spin frequency $ν$ inferred from previous rotation solutions, the newly$\textrm{-}$fitted $ν$ show differences larger than 10$^{-9}$ Hz for most pulsars. The contribution of the Shklovsky effect to period derivative $\dot{P}$ can be properly removed taking advantages of accurate proper motion and distance of target pulsars measured by VLBI astrometry. This further leads to a precise estimate of intrinsic characteristic age $τ_{\rm c}$. Differences between the newly$\textrm{-}$measured $τ_{\rm c}$ and corresponding previous results are as large as 2% for some pulsars. VLBI astrometric parameter solutions also lead to better measurements of timing irregularities. For PSR B0154$+$61, the glitch epoch (MJD 58279.5) measured with previous ephemeris is about 13 d later than the result (MJD 58266.4) obtained with VLBI astrometric parameter solutions.
