EXPLORING THE MORPHOLOGY OF RAVE STELLAR SPECTRA
EXPLORING THE MORPHOLOGY OF RAVE STELLAR SPECTRA
复制标题
探索 RAVE 恒星光谱的形态
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
R. Wyse
中科院分区：
文献类型：
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作者：
G. Matijevič;T. Zwitter;O. Bienaymé;J. Bland;C. Boeche;K. Freeman;B. Gibson;G. Gilmore;E. Grebel;A. Helmi;U. Munari;J. Navarro;Q. Parker;W. Reid;G. Seabroke;A. Siebert;A. Siviero;M. Steinmetz;F. Watson;M. Williams;R. Wyse
RAVE（英语：RAdial Velocity Experiment）是一个对银河系进行的中等分辨率（R 7500）光谱测量，已经获得了超过50万个恒星光谱。它们提供了一个随机选择的有限星等样本，因此使用可靠和自动化的分类方案来识别正常的单星并发现不同类型的特殊恒星是很重要的。为此，我们提出了一个形态分类的350000 RAVE调查恒星光谱使用局部线性嵌入，降维方法，使复杂的光谱形态表示在一个低维投影空间，同时仍然保留了本地邻居的光谱的属性。我们发现数据库中的绝大多数光谱（约90%-95%）属于正常的单星，但也有相当数量的几种类型的特殊星。其中，人口最多的群体是各种类型的光谱双星和色球活跃星。它们都包括几千个光谱。特别是后一组提供了重要的进一步调查的机会，因为活动的恒星是一个已知的代理恒星年龄。将同样的分类程序应用于正常的单恒星样本，表明二维空间中投影流形的形状与恒星温度、表面重力和金属丰度相关。
The RAdial Velocity Experiment (RAVE) is a medium-resolution (R ∼ 7500) spectroscopic survey of the Milky Way that has already obtained over half a million stellar spectra. They present a randomly selected magnitude-limited sample, so it is important to use a reliable and automated classification scheme that identifies normal single stars and discovers different types of peculiar stars. To this end, we present a morphological classification of ∼350, 000 RAVE survey stellar spectra using locally linear embedding, a dimensionality reduction method that enables representing the complex spectral morphology in a low-dimensional projected space while still preserving the properties of the local neighborhoods of spectra. We find that the majority of all spectra in the database (∼ 90%–95%) belong to normal single stars, but there is also a significant population of several types of peculiars. Among them, the most populated groups are those of various types of spectroscopic binary and chromospherically active stars. Both of them include several thousands of spectra. Particularly the latter group offers significant further investigation opportunities since activity of stars is a known proxy of stellar ages. Applying the same classification procedure to the sample of normal single stars alone shows that the shape of the projected manifold in two-dimensional space correlates with stellar temperature, surface gravity, and metallicity.