论文标题
对盖亚时代开放簇结构的新见解
New insights into the structure of open clusters in the Gaia era
论文作者
论文摘要
在Gaia数据的帮助下，注意到，除了核心组件外，开放簇的扩展区域中还有低密度的外光晕组件。为了研究群集的核心半径（$ \ sim $ 10 PC）以外的扩展结构，基于Gaia EDR3数据，最多可作为搜索半径为50 pc，我们使用pyupmask算法来重新确定1-2 kpc内开放群集的成员明星。我们获得了256个开放簇的成员恒星，尤其是位于开放群集外晕区域的恒星。此外，我们发现外部区域中大多数开放群集的径向密度分布都偏离了国王的轮廓。 To better describe the internal and external structural characteristics of open clusters, we propose a double components model for description: core components with King model distribution and outer halo components with logarithmic Gaussian distribution, and then suggest using four radii ( $r_c$, $r_t$, $r_o$, $r_e$) for describing the structure and distribution profile of star clusters, where $r_t$ and $r_e$ represent the核心组件和外光晕组件的边界。最后，我们提供了具有结构参数的256个簇的目录。此外，我们的研究表明，这些半径的大小在统计上是线性相关的，这表明群集的内部和外部区域相互关联并遵循类似的进化过程。此外，我们表明，两个组件的结构可用于更好地在不同阶段追踪群集演变属性。
With the help of Gaia data, it is noted that in addition to the core components, there are low-density outer halo components in the extended region of open clusters. To study the extended structure beyond the core radius of the cluster ($\sim$ 10 pc), based on Gaia EDR3 data, taking up to 50 pc as the searching radius, we use the pyUPMASK algorithm to re-determine the member stars of the open cluster within 1-2 kpc. We obtain the member stars of 256 open clusters, especially those located in the outer halo region of open clusters. Furthermore, we find that most open clusters' radial density profile in the outer region deviates from the King's profile. To better describe the internal and external structural characteristics of open clusters, we propose a double components model for description: core components with King model distribution and outer halo components with logarithmic Gaussian distribution, and then suggest using four radii ( $r_c$, $r_t$, $r_o$, $r_e$) for describing the structure and distribution profile of star clusters, where $r_t$ and $r_e$ represent the boundaries of core components and outer halo components respectively. Finally, we provide a catalog of 256 clusters with structural parameters. In addition, our study shows the sizes of these radii are statistically linear related, which indicates that the inner and outer regions of the cluster are interrelated and follow similar evolutionary processes. Further, we show that the structure of two components can be used to better trace the cluster evolution properties in different stages.
