Metallicities, relative ages and kinematics of stellar populations in omega Centauri release_las4s2rn5bho3cop4gz5xkci54

by A. Sollima, E. Pancino, F. R. Ferraro, M. Bellazzini, O. Straniero, L. Pasquini

Released as a article .



We present results of an extensive spectroscopic survey of Subgiant stars in the stellar system omega Centauri. Using infrared CaII triplet lines, we derived metallicities and radial velocities for more than 250 stars belonging to different stellar populations of the system. We find that the most metal rich component, the anomalous Sub Giant Branch (SGB-a), has a metallicity of [Fe/H] -0.6 fully compatible with that determined along the anomalous Red Giant Branch (RGB-a). Our analysis suggests that the age of this component and of the other metal-intermediate (-1.4 < [Fe/H] < -1.0) stellar populations of the system are all comparable to that of the dominant metal poor population within 2 Gyr regardless of any choice of helium abundance. These results impose severe constraints on the time-scale of the enrichment process of this stellar system, excluding the possibility of an extended star formation period. The radial velocity analysis of the entire sample demonstrates that only the metal-intermediate populations are kinematically cooler than the others.
In text/plain format

Archived Files and Locations

application/pdf  767.7 kB
file_4onz7u2usvhy7gh2v22pc5mfaa (archive)
Read Archived PDF
Preserved and Accessible
Type  article
Stage   submitted
Date   2005-09-05
Version   v1
Language   en ?
Work Entity
access all versions, variants, and formats of this works (eg, pre-prints)
Catalog Record
Revision: 627b23e3-45d4-4b04-af10-aa5d7f4965ab