Understanding the diversity in spectra is the key to determining the physical parameters of galaxies. The optical spectra of galaxies are highly convoluted with continuum and lines that are potentially sensitive to different physical parameters. Defining the wavelength regions of interest is therefore an important question. In this work, we identify informative wavelength regions in a single-burst stellar population model using the CUR Matrix Decomposition. Simulating the Lick/IDS spectrograph configuration, we recover the widely used D n (4000), Hβ, and Hδ A to be most informative. Simulating the Sloan Digital Sky Survey spectrograph configuration with a wavelength range 3450-8350 ? and a model-limited spectral resolution of 3 ?, the most informative regions are: first region—the 4000 ? break and the Hδ line; second region—the Fe-like indices; third region—the Hβ line; and fourth region—the G band and the Hγ line. A principal component analysis on the first region shows that the first eigenspectrum tells primarily the stellar age, the second eigenspectrum is related to the age-metallicity degeneracy, and the third eigenspectrum shows an anti-correlation between the strengths of the Balmer and the Ca K and H absorptions. The regions can be used to determine the stellar age and metallicity in early-type galaxies that have solar abundance ratios, no dust, and a single-burst star formation history. The region identification method can be applied to any set of spectra of the user's interest, so that we eliminate the need for a common, fixed-resolution index system. We discuss future directions in extending the current analysis to late-type galaxies. ASCII formatted tables of the regional eigenspectra are available.
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机译：了解光谱的多样性是确定星系物理参数的关键。星系的光谱与可能对不同物理参数敏感的连续体和谱线高度重叠。因此，定义感兴趣的波长区域是一个重要的问题。在这项工作中，我们使用CUR矩阵分解来识别单爆发恒星种群模型中的信息波长区域。通过模拟Lick / IDS光谱仪的配置，我们可以找到广泛使用的D n（4000），Hβ和HδA，以提供更多信息。模拟波长范围为3450-8350的Sloan Digital Sky Survey光谱仪配置？且模型限制的光谱分辨率为3？，最有用的区域是：第一个区域-4000？断裂和Hδ线;第二区域-类铁指数;第三区域-Hβ线;第四区-G带和Hγ线。对第一区域的主成分分析表明，第一特征谱主要反映了星体年龄，第二特征谱与年龄金属变性有关，而第三特征谱表明，Balmer和Ca K强度之间存在反相关关系。和氢吸收。这些区域可用于确定具有太阳丰度比，无尘埃和单爆发恒星形成历史的早期类型星系的星体年龄和金属性。区域识别方法可以应用于用户感兴趣的任何光谱集，因此我们不再需要通用的固定分辨率索引系统。我们讨论了将当前分析扩展到晚型星系的未来方向。区域特征谱的ASCII格式表可用。
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