Metallicity distributions of elliptical galaxies and globular cluster systems - Absorption line strength gradients in elliptical galaxies

Citation
N. Arimoto et C. Kobayashi, Metallicity distributions of elliptical galaxies and globular cluster systems - Absorption line strength gradients in elliptical galaxies, ASTRO SP SC, 265(1-4), 1999, pp. 513-521
Citations number
28
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICS AND SPACE SCIENCE
ISSN journal
0004640X → ACNP
Volume
265
Issue
1-4
Year of publication
1999
Pages
513 - 521
Database
ISI
SICI code
0004-640X(1999)265:1-4<513:MDOEGA>2.0.ZU;2-K
Abstract
Gradients of absorption line indices are studied and mean stellar metallici ties are estimated for 46 elliptical galaxies. The mean stellar metalliciti es range from [[Fe/H]] similar or equal to -0.8 to +0.2 and ellipticals wit h smaller central velocity dispersions tend to have lower [[Fe/H]]; thus th e mass-metallicity relation holds not only for the galaxy center but also f or the whole part of the galaxy. There is an evidence that the magnesium is enhanced systematically in all ellipticals by 0.2 dex with respect to the iron. Giant elliptical galaxies show lack of metal-poor stars (the G-dwarf problem). Metal-poor globular clusters of ellipticals formed well in advanc e of the formation of metal-rich ones which formed simultaneously with the bulk of stars of mother galaxies under the influence of galaxy chemical enr ichment. The bimodal [Fe/H] distribution of globular clusters does not nece ssarily mean that elliptical galaxies formed by the mergers of disc galaxie s.