Abstract

We have studied the kinematic properties of young pre-main-sequence stars. We have selected these stars based on data from the Gaia DR2 catalogue by invoking a number of photometric infrared surveys. Using 4564 stars with parallax errors less than 20%, we have found the following parameters of the angular velocity of Galactic rotation: \({{\Omega }_{0}} = 28.84 \pm 0.10\) km s^–1 kpc^–1, \(\Omega _{0}^{'} = - 4.063 \pm 0.029\) km s^–1 kpc^–2, and \(\Omega _{0}^{{''}} = 0.766 \pm 0.020\) km s^–1 kpc^–3, where the Oort constants are \(A = 16.25 \pm 0.33\) km s^–1 kpc^–1 and \(B = - 12.58 \pm 0.34\) km s^–1 kpc^–1. The circular rotation velocity of the solar neighborhood around the Galactic center is \({{V}_{0}} = 230.7 \pm 4.4\) km s^–1 for the adopted Galactocentric distance of the Sun \({{R}_{0}} = 8.0 \pm 0.15\) kpc. The residual velocity dispersion for the stars considered is shown to be low, suggesting that they are extremely young. The residual velocity dispersion averaged over three coordinates is ~11 km s^–1 for Herbig Ae/Be stars and ~7 km s^–1 for T Tauri stars.

中文翻译：

---

Gaia DR2目录中年轻的中低质量恒星的运动学特性

摘要

我们研究了年轻的主序前恒星的运动学特性。我们通过调用许多光度红外勘测，基于Gaia DR2目录中的数据选择了这些恒星。使用4564颗视差误差小于20％的恒星，我们发现了银河系旋转角速度的以下参数：\（{{\ Omega} _ {0}} = 28.84 \ pm 0.10 \） km s ^–1 kpc ^{– 1}，\（\ Omega _ {0} ^ {'} =-4.063 \ pm 0.029 \） km s ^–1 kpc ^–2和\（\ Omega _ {0} ^ {{''}} = 0.766 \ pm 0.020 \） km s ^–1 kpc ^–3，其中奥尔特常数为\（A = 16.25 \ pm 0.33 \） km s ^–1kpc ^–1和\（B =-12.58 \ pm 0.34 \） km s ^–1 kpc ^–1。周围的银心太阳附近的圆形旋转速度是\（{{V} _ {0}} = 230.7 \ PM 4.4 \）公里S ^-1为太阳的通过银心距\（{{R} _ {0}} = 8.0 \ pm 0.15 \） kpc。所研究的恒星的剩余速度色散显示为低，表明它们非常年轻。残余速度色散平均超过三个坐标被〜11公里S ^-1为赫比格Ae / Be星和-7公里S ^-1为金牛T星。