AGE AND ABUNDANCE EFFECTS IN SINGLE-STELLAR POPULATIONS

被引:59
作者
BORGES, AC [1 ]
IDIART, TP [1 ]
DEFREITAS, JA [1 ]
THEVENIN, F [1 ]
机构
[1] OBSERV NICE,OCA,F-06304 NICE 4,FRANCE
关键词
D O I
10.1086/117700
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The present article proposes new fitting formulas for the indices Mg-2 and Na D as functions of stellar parameters but including explicitly the abundance ratio of the relevant element. Integrated metallicity indices for single-stellar populations like, Mg-2, [Fe], Na D, H beta, and (B - V) color have been computed for a grid of 100 models as a function of age, metallicity, and relative abundances which stimulate a medium enriched purely by type II supernova, or a mix of both types I and II. Different diagrams show model self-consistency, in that most globular clusters appear to have ages larger than 12 Gyr and an average abundance ratio [Mg/Fe]=0.34. Interpolation formulas based on our model computations are given for the different indices as functions of age, metallicity, and relative abundances (C) 1995 American Astronomical Society.
引用
收藏
页码:2408 / 2414
页数:7
相关论文
共 22 条
[1]   A CALIBRATION OF MG2 VERSUS [FE/H] AND [MG/FE] [J].
BARBUY, B .
ASTROPHYSICAL JOURNAL, 1994, 430 (01) :218-221
[2]  
BRESSAN A, 1993, ASTRON ASTROPHYS SUP, V100, P647
[3]   OLD STELLAR POPULATIONS .1. A SPECTROSCOPIC COMPARISON OF GALACTIC GLOBULAR-CLUSTERS, M31 GLOBULAR-CLUSTERS, AND ELLIPTICAL GALAXIES [J].
BURSTEIN, D ;
FABER, SM ;
GASKELL, CM ;
KRUMM, N .
ASTROPHYSICAL JOURNAL, 1984, 287 (02) :586-609
[4]   THE MAGNESIUM MG-2 INDEX AS AN INDICATOR OF METALLICITY IN ELLIPTIC GALAXIES [J].
BUZZONI, A ;
GARIBOLDI, G ;
MANTEGAZZA, L .
ASTRONOMICAL JOURNAL, 1992, 103 (06) :1814-1827
[5]   AGES OF GLOBULAR-CLUSTERS AND HELIUM DIFFUSION [J].
CHABOYER, B ;
SARAJEDINI, A ;
DEMARQUE, P .
ASTROPHYSICAL JOURNAL, 1992, 394 (02) :515-522
[6]  
CHIEFFI A, 1991, ASP C SER, V13, P219
[7]  
DESTROBEL GC, 1992, ASTRON ASTROPHYS SUP, V95, P273
[8]   OLD STELLAR POPULATIONS .2. AN ANALYSIS OF K-GIANT SPECTRA [J].
FABER, SM ;
FRIEL, ED ;
BURSTEIN, D ;
GASKELL, CM .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1985, 57 (04) :711-741
[9]  
FAGOTTO F, 1994, ASTRON ASTROPHYS SUP, V104, P365
[10]  
FAGOTTO F, 1994, ASTRON ASTROPHYS SUP, V105, P29