论文标题
与Gaia DR2进行OBSSociat的内部动作
Internal motions in OB-associations with Gaia DR2
论文作者
论文摘要
我们通过使用GAIA DR2适当的动作来研究28个OB缔合内部的运动。计算出28个OB缔合的平均速度分散剂，其中包括20颗恒星具有GAIA DR2适当运动的速度为Sigma_V = 4.5 km S-1。 ob缔合的中位病毒和恒星质量为m_vir = 8.9 x 10^5和m_st = 8.1 x 10^3 ms。母体巨型分子云中的恒星形成效率似乎为Epsilon = 1.2％。 GAIA DR2的适当动作证实了Per OB1，CAR OB1和SGR OB1关联的扩展，与Gaia DR1数据相结合。我们还检测到GEM OB1，ORI OB1和SCO OB1关联的扩展，当使用GAIA DR2适当的运动进行分析时，这是第一次可能。对PER OB1关联中OB-Star的分布的分析表明，存在40 PC的壳状结构。可能，PER OB1关联的膨胀始于速度大于等于5.0 +\ -1.7 km S-1的当今膨胀速度。
We study the motions inside 28 OB-associations with the use of Gaia DR2 proper motions. The average velocity dispersion calculated for 28 OB-associations including more than 20 stars with Gaia DR2 proper motion is sigma_v =4.5 km s-1. The median virial and stellar masses of OB-associations are M_vir=8.9 x 10^5 and M_st=8.1 x 10^3 Ms, respectively. The median star-formation efficiency in parent giant molecular clouds appears to be epsilon=1.2 per cent. Gaia DR2 proper motions confirm the expansion in the Per OB1, Car OB1 and Sgr OB1 associations found earlier with Gaia DR1 data. We also detect the expansion in Gem OB1, Ori OB1 and Sco OB1 associations which became possible for the first time now when analyzed with Gaia DR2 proper motions. The analysis of the distribution of OB-stars in the Per OB1 association shows the presence of a shell-like structure with the radius of 40 pc. Probably, the expansion of the Per OB1 association started with the velocity greater than the present-day expansion velocity equal to 5.0 +\- 1.7 km s-1.
