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Astron. Astrophys. 330, L33-L36 (1998)
Letter to the Editor
Field halo stars: the globular cluster connection *
E. Jehin,
P. Magain
**,
C. Neuforge
***,
A. Noels and
A.A. Thoul
Institut d'Astrophysique et de Géophysique,
Université de Liège, 5, avenue de Cointe, B-4000
Liège, Belgium
Received 28 October 1997 / Accepted 14 November 1997
Abstract
High resolution and high signal-to-noise spectra of about 20 metal-poor stars have been analysed. The correlations between the relative abundances of 16 elements have been studied, with a special emphasis on the neutron-capture ones.
This analysis reveals the existence of two subpopulations of field
halo stars, namely Pop IIa and Pop IIb. They differ by the behaviour
of the s -process elements versus the ![[FORMULA]](img1.gif)
and
r -process elements.
A scenario for the formation of these stars is presented, which closely relates the origin of field halo stars to the evolution of globular clusters. According to this scenario, the two sub-populations originate from two different stages in the globular cluster's chemical evolution.
* Based on observations carried out at the European Southern Observatory (La Silla, Chile)
** Maître de Recherches au Fonds National Belge de la Recherche Scientifique
*** Chargé de Recherches au Fonds National Belge de la Recherche Scientifique
Contents
- 1. Introduction
- 2. Quality of the spectroscopic data
- 3. Highlights of the abundance correlations
- 4. Tentative scenario
- Acknowledgements
- References
© European Southern Observatory (ESO) 1998
Online publication: January 16, 1998
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