论文标题
使用恒星运动学的距离到砖云的距离
Distance to the Brick cloud using stellar kinematics
论文作者
论文摘要
语境。目前正在深入研究银河系中心的中央分子区，以了解在银河核的极端条件下恒星形成如何进行。 Knowing the position of molecular clouds along the line of sight toward the Galactic center has had important implications in our understanding of the physics of the gas and star formation in the central molecular zone.It was recently claimed that the dense molecular cloud G0.253 + 0.016 (the Brick) has a distance of $\sim$7.20 kpc from the Sun.那将将其放在中央分子区域之外，因此将其放在核恒星磁盘之外，但仍在凸起内。 目标。理论考虑以及观察性研究表明，属于核恒星磁盘的恒星与属于内部凸起的恒星具有不同的运动学。因此，我们旨在通过研究该区域的恒星的适当运动来限制与砖的距离。 结果。向核恒星磁盘上看到的恒星种群显示了以下三个运动学成分：1）凸起的恒星，各向同性速度分散$ \ sim $ 3.5 $ 3.5微弧度每年第二秒； 2）向东移动的恒星在核恒星磁盘的近侧； 3）在核恒星磁盘远端向西移动的恒星。我们清楚地看到了所有三个组件朝向比较字段。但是，朝着砖块挡住其后面恒星的光线，我们只能看到运动学成分1）和2）。 结论。砖块从核恒星磁盘远端的恒星中阻断光线，但检测向东流星的重要组成部分意味着砖必须位于核恒星磁盘内，因此它构成了中央分子区域的一部分。
Context. The central molecular zone at the Galactic center is currently being studied intensively to understand how star formation proceeds under the extreme conditions of a galactic nucleus. Knowing the position of molecular clouds along the line of sight toward the Galactic center has had important implications in our understanding of the physics of the gas and star formation in the central molecular zone.It was recently claimed that the dense molecular cloud G0.253 + 0.016 (the Brick) has a distance of $\sim$7.20 kpc from the Sun. That would place it outside of the central molecular zone, and therefore of the nuclear stellar disk, but still inside the Bulge. Aims. Theoretical considerations as well as observational studies show that stars that belong to the nuclear stellar disk have different kinematics from those that belong to the inner Bulge. Therefore, we aim to constrain the distance to the Brick by studying the proper motions of the stars in the area. Results. The stellar population seen toward the nuclear stellar disk shows the following three kinematic components: 1) Bulge stars with an isotropic velocity dispersion of $\sim$3.5 micro-arc second per year; 2) eastward moving stars on the near side of the nuclear stellar disk; and 3) westward moving stars on the far side of the nuclear stellar disk. We clearly see all three components toward the comparison field. However, toward the Brick, which blocks the light from stars behind it, we can only see kinematic components 1) and 2). Conclusions. While the Brick blocks the light from stars on the far side of the nuclear stellar disk, the detection of a significant component of eastward streaming stars implies that the Brick must be located inside the nuclear stellar disk and, therefore, that it forms part of the central molecular zone.
