The ratio of α-elements to iron in early-type galaxies from TiO and Mg2

被引：14

作者：

Milone, A

Barbuy, B

Schiavon, RP

机构：

[1] Inst Nacl Pesquisas Espaciais, MCT, Div Astrofis, BR-12227010 Sao Jose Dos Campos, Brazil

[2] Univ Sao Paulo, IAG, Dept Astron, BR-01060970 Sao Paulo, Brazil

[3] Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA

来源：

ASTRONOMICAL JOURNAL | 2000年 / 120卷 / 01期

关键词：

galaxies : abundances; galaxies : elliptical and lenticular; cD; galaxies : stellar content;

D O I：

10.1086/301434

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

In order to derive the ratio of alpha-elements to iron in galaxies, we have observed the strongest TiO band heads of the gamma and gamma' systems at 7000-7500 Angstrom in a sample of a dozen early-type galaxies. The equivalent widths of the TiO bands are compared with synthetic spectra for single-aged stellar populations and composite galaxy models, all computed with [alpha/Fe] = 0.0 and +0.3. The same method is also applied to the (Fe) and Mg-2 Lick indices for the sample galaxies. The results obtained are [Ti/Fe] approximate to [Mg/Fe] approximate to +0.3, indicating a clear enhancement of the alpha-elements-to-iron ratio for our sample of early-type galaxies.

引用

页码：131 / 138

页数：8