Open Cluster Chemical Homogeneity throughout the Milky Way
Open Cluster Chemical Homogeneity throughout the Milky Way
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DOI：
10.3847/1538-4357/abb93e
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发表时间：
2020-09
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影响因子：
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通讯作者：
Vijith Jacob Poovelil;G. Zasowski;S. Hasselquist;Anil C. Seth;J. Donor;R. Beaton;Katia Cunha
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作者：
Vijith Jacob Poovelil;G. Zasowski;S. Hasselquist;Anil C. Seth;J. Donor;R. Beaton;Katia Cunha
幸存的星团的化学均匀性包含了关于星际介质（ISM）混合效率、星星形成和银河系富集历史的重要线索。在少数疏散星团的现有测量表明，在0.03 dex水平的几个元素的同质性。在这里，我们提出了（一）一个新的集群成员目录的基础上，只有APOGEE径向速度和盖亚-DR 2自行，（二）改进丰度的不确定性APOGEE集群成员，和（iii）集群的均匀性对银河系和集群属性的依赖，使用丰度的八个元素从APOGEE调查的10个高质量的集群。我们发现星系团的同质性与银心距、年龄和金属丰度无关。然而，速度分散，这是集群质量的代理，是正相关的内在散射在相对较高的水平上的显着性[Ca/Fe]和[Mg/Fe]。我们还看到[Ni/Fe]、[Si/Fe]、[Al/Fe]和[Fe/H]在低显著性水平下可能正相关，而[Cr/Fe]和[Mn/Fe]不相关。与速度色散相关的元素主要是由核心坍缩超新星（CCSNe）产生的。然而，小样本量和相对较低的相关性显著性突出了后续研究的必要性。如果未来的研究证实，这些发现将表明主要由Ia型SNe和CCSNe产生的元素的相关长度之间存在定量差异，这将对银河系化学演化模型和化学标记的可行性产生影响。
The chemical homogeneity of surviving stellar clusters contains important clues about interstellar medium (ISM) mixing efficiency, star formation, and the enrichment history of the Galaxy. Existing measurements in a handful of open clusters suggest homogeneity in several elements at the 0.03 dex level. Here we present (i) a new cluster member catalog based only on APOGEE radial velocities and Gaia-DR2 proper motions, (ii) improved abundance uncertainties for APOGEE cluster members, and (iii) the dependence of cluster homogeneity on Galactic and cluster properties, using abundances of eight elements from the APOGEE survey for 10 high-quality clusters. We find that cluster homogeneity is uncorrelated with Galactocentric distance, , age, and metallicity. However, velocity dispersion, which is a proxy for cluster mass, is positively correlated with intrinsic scatter at relatively high levels of significance for [Ca/Fe] and [Mg/Fe]. We also see a possible positive correlation at a low level of significance for [Ni/Fe], [Si/Fe], [Al/Fe], and [Fe/H], while [Cr/Fe] and [Mn/Fe] are uncorrelated. The elements that show a correlation with velocity dispersion are those that are predominantly produced by core-collapse supernovae (CCSNe). However, the small sample size and relatively low correlation significance highlight the need for follow-up studies. If borne out by future studies, these findings would suggest a quantitative difference between the correlation lengths of elements produced predominantly by Type Ia SNe versus CCSNe, which would have implications for Galactic chemical evolution models and the feasibility of chemical tagging.