论文标题
我们银河最年轻的光盘
Our Galaxy's youngest disc
论文作者
论文摘要
我们通过将新家庭的分布功能（DFS）拟合到五维GAIA数据的样本中，以$ 47 \，000 $ ob stars的样本拟合，研究了银河系的年轻恒星光盘的结构。拟合程序的测试表明，如果完全知道银河灰尘的分布，则Young Disc的DF将受到GAIA数据的强烈限制。最适合真实数据的DF可以准确地预测恒星在观察到的位置的运动学，但它可以预测恒星的空间分布较差，几乎可以肯定，由于最可取的灰尘图中的误差。我们认为，通过修改灰尘模型，直到DF与数据一致的恒星的空间分布可以大大改善灰尘模型。预计OB恒星的表面密度将在$ r \ simeq5.5 \ mbox {kpc} $峰值达到峰值，在分子气表面密度的报道峰值略微以外；我们认为，通过使用较差的运动距离，后者的半径可能被低估了。最佳拟合DF预测的速度分布，具有测量的视线速度$ v_ \并行$表明，外部光盘在10 $ \ mbox {km}〜\ mbox {km}〜\ mbox {s}^{ - s}^{ - 1} $中的较早研究中的$ v_ \ v _ \ v _的值有效，并有效。二进制。因此，外盘比有时据报道要冷。
We investigate the structure of our Galaxy's young stellar disc by fitting the distribution functions (DFs) of a new family to five-dimensional Gaia data for a sample of $47\,000$ OB stars. Tests of the fitting procedure show that the young disc's DF would be strongly constrained by Gaia data if the distribution of Galactic dust were accurately known. The DF that best fits the real data accurately predicts the kinematics of stars at their observed locations, but it predicts the spatial distribution of stars poorly, almost certainly on account of errors in the best-available dust map. We argue that dust models could be greatly improved by modifying the dust model until the spatial distribution of stars predicted by a DF agreed with the data. The surface density of OB stars is predicted to peak at $R\simeq5.5\mbox{kpc}$, slightly outside the reported peak in the surface density of molecular gas; we suggest that the latter radius may have been under-estimated through the use of poor kinematic distances. The velocity distributions predicted by the best-fit DF for stars with measured line-of-sight velocities $v_\parallel$ reveal that the outer disc is disturbed at the level of 10 $\mbox{km}~\mbox{s}^{-1}$ in agreement with earlier studies, and that the measured values of $v_\parallel$ have significant contributions from the orbital velocities of binaries. Hence the outer disc is colder than it is sometimes reported to be.
