The Galactic spiral structure as revealed by O- and early B-type stars
The Galactic spiral structure as revealed by O- and early B-type stars
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O型和早期B型恒星揭示的银河螺旋结构
DOI：
10.1093/mnras/stz1357
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发表时间：
2019
影响因子：
4.8
通讯作者：
Liu X W
中科院分区：
文献类型：
--
作者：
Chen B Q;Huang Y;Hou L G;Tian H;Li G X;Yuan H B;Wang H F;Wang C;Tian Z J;Liu X W
我们调查的形态和运动学的银河系的螺旋结构的基础上的一个新的样本的O型和早期的B型恒星。我们从VST测光H$\alpha$巡天数据发布2（VPHAS+ DR 2）和盖亚数据发布2（盖亚DR 2）的组合数据中选择了6，858个高度自信的OB星星候选者。连同O-B2恒星从文献中，我们建立了一个样本组成的14,880 O-和早期B型恒星，所有盖亚视差不确定性小于20%.The新的样本，迄今为止最大的一个O-和早期B型恒星与强大的距离和自行估计，覆盖银河系平面的距离高达$\sim $6千秒差距从太阳。该样本使我们能够非常详细地检查盾牌，人马座，本地和英仙座臂的形态。O型和早期B型恒星所描绘的银河系螺旋结构显示出絮状的图案。精确的结构参数，以及每个螺旋臂的垂直速度分布的平均值和分散度。
We investigate the morphology and kinematics of the Galactic spiral structure based on a new sample of O- and early B-type stars. We select 6,858 highly confident OB star candidates from the combined data of the VST Photometric H$\alpha$ Survey Data Release 2 (VPHAS+ DR2) and the Gaia Data Release 2 (Gaia DR2). Together with the O-B2 stars from the literature, we build a sample consisting of 14,880 O- and early B-type stars, all with Gaia parallax uncertainties smaller than 20 per cent. The new sample, hitherto the largest one of O- and early B-type stars with robust distance and proper motion estimates, covers the Galactic plane of distances up to $\sim$ 6 kpc from the Sun. The sample allows us to examine the morphology of the Scutum, Sagittarius, Local and Perseus Arms in great detail. The spiral structure of the Milky Way as traced by O- and early B-type stars shows flocculent patterns. Accurate structure parameters, as well as the means and dispersions of the vertical velocity distributions of the individual Spiral Arms are presented.