Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2009-12-21
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
22 pages, 8 eps figures, in press in New Astronomy
Scientific paper
The globular cluster $\omega$ Centauri (NGC 5139) is a puzzling stellar system harboring several distinct stellar populations whose origin still represents a unique astrophysical challenge. Current scenarios range from primordial chemical inhomogeneities in the mother cloud to merging of different sub-units and/or subsequent generations of enriched stars - with a variety of different pollution sources- within the same potential well. In this paper we study the chemical abundance pattern in the outskirts of Omega Centauri, half-way to the tidal radius (covering the range of 20-30 arcmin from the cluster center), and compare it with chemical trends in the inner cluster regions, in an attempt to explore whether the same population mix and chemical compositions trends routinely found in the more central regions is also present in the cluster periphery.We extract abundances of many elements from FLAMES/UVES spectra of 48 RGB stars using the equivalent width method and then analyze the metallicity distribution function and abundance ratios of the observed stars. We find, within the uncertainties of small number statistics and slightly different evolutionary phases, that the population mix in the outer regions cannot be distinguished from the more central regions, although it is clear that more data are necessary to obtain a firmer description of the situation. From the abundance analysis, we did not find obvious radial gradients in any of the measured elements.
Carraro Giovanni
Marconi Gianni
Scarpa Riccardo
Villanova Sandro
No associations
LandOfFree
Abundance analysis of a sample of evolved stars in the outskirts of Omega Centauri does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Abundance analysis of a sample of evolved stars in the outskirts of Omega Centauri, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Abundance analysis of a sample of evolved stars in the outskirts of Omega Centauri will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-302639