Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Principal component analysis for spectral indices of stellar populations   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 B, we find that some other spectral indices
have great potential to determine the age of stellar populations, such as
G4300, Fe4383, C24668, and Mgb. In addition, we find that the sensitivity to
age of these spectral indices depends on the metallicity of the simple stellar
population (SSP): H B and G4300 are more suited to determine the age of the
low-metallicity stellar population, C24668 and Mgb 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.

37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys