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arXiv 0912.0413astro-ph.CO
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测试星团恒星星族的光谱模型:II。结果

Testing spectral models for stellar populations with star clusters: II. Results

Rosa M. Gonzalez Delgado, Roberto Cid Fernandes

摘要:

高光谱分辨率的进化合成模型已成为河外研究中经常使用的组成部分,因此值得进行彻底的测试。星团是进行此类测试的理想实验室。本文应用光谱拟合的方法概述了文件I的样本的集群,主要是从麦哲伦云和跨越广泛的年龄和金属丰度,拟合他们的综合光谱与一套现代演化合成模型的单个恒星星族。本研究中采用的模型加光谱库的组合是Galaxev/STELIB、Vazdekis/MILES、SED@/GRANADA和Galaxev/MILES+GRANADA,它们提供了目前可用于光谱拟合工作的模型的代表性样本。一系列的实证检验与这些模型进行,比较质量的光谱拟合和年龄,金属丰度和消光与他们每个人获得的值。从这些光谱拟合和文献数据,这些附近的,充分研究的集群之间的属性也进行了比较。进行这些比较的总目标是为模型制作者提供有用的反馈,并为这些模型的用户提供指导。我们发现,使用GRANADA和MILES库的新一代模型在光谱拟合质量和检索年龄和金属丰度的准确性方面都优于基于STELIB的模型。只要模型的外推不超出其预期的有效性范围,就可以实现约0.1德克斯的年龄和0.3德克斯的金属丰度的准确性。

英文摘要:

High spectral resolution evolutionary synthesis models have become a routinely used ingredient in extragalactic work, and as such deserve thorough testing. Star clusters are ideal laboratories for such tests. This paper applies the spectral fitting methodology outlined in Paper I to a sample of clusters, mainly from the Magellanic Clouds and spanning a wide range in age and metallicity, fitting their integrated light spectra with a suite of modern evolutionary synthesis models for single stellar population. The combinations of model plus spectral library employed in this investigation are Galaxev/STELIB, Vazdekis/MILES, SED@/GRANADA, and Galaxev/MILES+GRANADA, which provide a representative sample of models currently available for spectral fitting work. A series of empirical tests are performed with these models, comparing the quality of the spectral fits and the values of age, metallicity and extinction obtained with each of them. A comparison is also made between the properties derived from these spectral fits and literature data on these nearby, well studied clusters. These comparisons are done with the general goal of providing useful feedback for model makers, as well as guidance to the users of such models. We find that new generation of models using the GRANADA and MILES libraries are superior to STELIB-based models both in terms of spectral fit quality and regarding the accuracy with which age and metallicity are retrieved. Accuracies of about 0.1 dex in age and 0.3 dex in metallicity can be achieved as long as the models are not extrapolated beyond their expected range of validity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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