论文标题
在年轻大型簇的主序列上搜索球状簇化学异常
Searching for globular cluster chemical anomalies on the main sequence of a young massive cluster
论文作者
论文摘要
球状簇中发现的星到明星丰度变化的光谱和光度信号似乎与群集的金属性，质量和年龄等全局参数相关。了解这种行为可能会使我们更接近这些有趣的丰度差。在这项工作中，我们使用深HST光度法来寻找年轻大型群集NGC 419（$ \ sim10^5 $ m $ _ {\ odot} $，$ \ sim1.4 $ gyr）的主要序列中丰度变化的证据。与以前的研究不同，在这里，我们专注于在旧球形的同一质量范围内的星星（$ \ sim0.75-1 $ m $ _ {\ odot} $），其中检测到了光元素变化。我们没有发现这些恒星在$ UN-B $和NGC 419的$ U-B $ CMD中的含量变化的证据。这与在47 TUC，NGC 6352和NGC 6637（NGC 6637）等旧球形中发现的N变量可能与NGC 419的金属相似，但具有与NGC 419的特征相似。在这个年轻的集群中，我们无法得出结论，这种效果是否主要由其年龄或质量驱动。
The spectroscopic and photometric signals of the star-to-star abundance variations found in globular clusters seem to be correlated with global parameters like the cluster's metallicity, mass and age. Understanding this behaviour could bring us closer to the origin of these intriguing abundance spreads. In this work we use deep HST photometry to look for evidence of abundance variations in the main sequence of a young massive cluster NGC 419 ($\sim10^5$ M$_{\odot}$, $\sim1.4$ Gyr). Unlike previous studies, here we focus on stars in the same mass range found in old globulars ($\sim0.75-1$ M$_{\odot}$), where light elements variations are detected. We find no evidence for N abundance variations among these stars in the $Un-B$ and $U-B$ CMD of NGC 419. This is at odds with the N-variations found in old globulars like 47 Tuc, NGC 6352 and NGC 6637 with similar metallicity to NGC 419. Although the signature of the abundance variations characteristic of old globulars appears to be significantly smaller or absent in this young cluster, we cannot conclude if this effect is mainly driven by its age or its mass.
