On the metallicity of open clusters. III. Homogenised sample
On the metallicity of open clusters. III. Homogenised sample
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DOI：
10.1051/0004-6361/201526370
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发表时间：
2015-11
期刊：
影响因子：
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通讯作者：
M. Netopil;E. Paunzen;U. Heiter;C. Soubiran
中科院分区：
文献类型：
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作者：
M. Netopil;E. Paunzen;U. Heiter;C. Soubiran
疏散星团被认为是银河研究各个主题的优秀工具。例如，它们可以准确追踪银河盘的化学结构。然而，只有相当低比例的疏散星团群体的金属丰度是已知的，并且这些值基于多种方法和数据。因此，非常需要大量且均匀的样本。在我们系列的第三部分中，我们使用各种不同的来源编制了均质疏散簇金属丰度的大样本。这些数据和造父变星样本用于研究径向金属丰度梯度、年龄效应并测试当前模型。我们使用光度和光谱数据来推导簇金属丰度。检查并测试了不同来源的可能偏移和相关性。总共得出了 172 个疏散星团的金属丰度。我们使用 100 个物体的光谱数据来研究径向金属丰度分布和年龄-金属丰度关系。我们发现金属丰度可能随着年龄的增长而增加，如果得到证实，将为径向迁移提供观测证据。尽管给出了统计显着性，但肯定需要更多的研究来排除选择效应等。疏散星团和造父变星与最近的银河系模型的比较总体上非常吻合。然而，这些模型并没有再现外盘中疏散星团的平坦梯度。因此，模型中要么低估了径向迁移的影响，要么有额外的机制在起作用。 [简略]
Open clusters are known as excellent tools for various topics in Galactic research. For example, they allow accurately tracing the chemical structure of the Galactic disc. However, the metallicity is known only for a rather low percentage of the open cluster population, and these values are based on a variety of methods and data. Therefore, a large and homogeneous sample is highly desirable. In the third part of our series we compile a large sample of homogenised open cluster metallicities using a wide variety of different sources. These data and a sample of Cepheids are used to investigate the radial metallicity gradient, age effects, and to test current models. We used photometric and spectroscopic data to derive cluster metallicities. The different sources were checked and tested for possible offsets and correlations. In total, metallicities for 172 open cluster were derived. We used the spectroscopic data of 100 objects for a study of the radial metallicity distribution and the age-metallicity relation. We found a possible increase of metallicity with age, which, if confirmed, would provide observational evidence for radial migration. Although a statistical significance is given, more studies are certainly needed to exclude selection effects, for example. The comparison of open clusters and Cepheids with recent Galactic models agrees well in general. However, the models do not reproduce the flat gradient of the open clusters in the outer disc. Thus, the effect of radial migration is either underestimated in the models, or an additional mechanism is at work. [abridged]