Principal component analysis for spectral indices of stellar populations |
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| Authors: | X Kong F Z Cheng |
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| Institution: | Centre for Astrophysics, University of Science and Technology of China, 230026 Hefei, China;National Astronomical Observatories, Beijing Astrophysics Centre, Chinese Academy of Sciences, 100012 Beijing, China |
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| Abstract: | We apply the method of principal component analysis to a sample of simple stellar populations to select some age-sensitive spectral indices. Besides the well-known age-sensitive index, H β , we find that some other spectral indices have great potential to determine the age of stellar populations, such as G4300, Fe4383, C24668, and Mg b . In addition, we find that the sensitivity to age of these spectral indices depends on the metallicity of the simple stellar population (SSP): H β and G4300 are more suited to determine the age of the low-metallicity stellar population, C24668 and Mg b are more suited to the high-metallicity stellar population. The results suggest that the principal component analysis method provides a more objective and informative alternative to diagnostics by individual spectral lines. |
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| Keywords: | methods: data analysis galaxies: evolution galaxies: fundamental parameters galaxies: star clusters |
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