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
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.