论文标题
Viscacha调查-VI。麦哲伦云中82星簇结构的尺寸研究
The VISCACHA survey -- VI. Dimensional study of the structure of 82 star clusters in the Magellanic Clouds
论文作者
论文摘要
我们使用Viscacha调查的数据介绍了位于大麦芽云的外部区域和小麦哲伦云的82星簇的内部结构的研究。通过构造最小跨越树(分析给定簇中恒星的相对位置),可以表征内部结构并探索每个群集的分形或亚聚集分布。我们计算了参数m(这是由区域归一化的连接段的平均长度),s(这是群集半径单位的平均点分离)和q(这些组件的比率)。这些参数可用于区分恒星的径向,同质和下结构分布。还研究了这些参数具有不同特征的依赖性,例如它们的年龄和空间分布。我们发现,大多数研究的簇呈现出均匀的恒星分布或径向浓度的分布。我们的结果与模型一致,这表明更动态发展的簇似乎具有较大的Q值,从而证实了数值模拟的先前结果。在群集的内部结构与它们的半乳酸距离之间似乎也存在相关性,从某种意义上说,对于两个星系,较远的簇都具有较大的Q值。我们还特别关注非成员田间恒星污染的影响及其后果,发现野外恒星去污染对于这类研究至关重要。
We present a study of the internal structure of 82 star clusters located at the outer regions of the Large Magellanic Cloud and the Small Magellanic Cloud using data of the VISCACHA Survey. Through the construction of the minimum spanning tree, which analyzes the relative position of stars within a given cluster, it was possible to characterize the internal structure and explore the fractal or subclustered distribution for each cluster. We computed the parameters m (which is the average length of the connected segments normalized by the area), s (which is the mean points separation in units of cluster radius), and Q (the ratio of these components). These parameters are useful to distinguish between radial, homogeneous, and substructured distributions of stars. The dependence of these parameters with the different characteristics of the clusters, such as their ages and spatial distribution, was also studied. We found that most of the studied clusters present a homogeneous stellar distribution or a distribution with a radial concentration. Our results are consistent with the models, suggesting that more dynamically evolved clusters seem to have larger Q values, confirming previous results from numerical simulations. There also seems to be a correlation between the internal structure of the clusters and their galactocentric distances, in the sense that for both galaxies, the more distant clusters have larger Q values. We also paid particular attention to the effects of contamination by non-member field stars and its consequences finding that field star decontamination is crucial for these kinds of studies.