The subgiant branch of ω Centauri seen through high-resolution spectroscopy. I. The first stellar generation in ω Cen?

@article{Pancino2011TheSB,
  title={The subgiant branch of $\omega$ Centauri seen through high-resolution spectroscopy. I. The first stellar generation in $\omega$ Cen?},
  author={E. Pancino and A. Mucciarelli and L. Sbordone and M. Bellazzini and L. Pasquini and L. Monaco and F. Ferraro},
  journal={Astronomy and Astrophysics},
  year={2011},
  volume={527},
  pages={1-15}
}
We analysed high-resolution UVES spectra of six stars belonging to the subgiant branch of ω Centauri, and derived abundance ratios of 19 chemical elements (namely Al, Ba, C, Ca, Co, Cr, Cu, Fe, La, Mg, Mn, N, Na, Ni, Sc, Si, Sr, Ti, and Y). A comparison with previous abundance determinations for red giants provided remarkable agreement and allowed us to identify the sub-populations to which our targets belong. We found that three targets belong to a low-metallicity population at [Fe/H] � –2.0… Expand
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References

SHOWING 1-10 OF 76 REFERENCES
Metallicities, Relative Ages, and Kinematics of Stellar Populations in ω Centauri*
We present results of an extensive spectroscopic survey of subgiant stars in the stellar system ω Cen. Using infrared Ca II triplet lines, we derived metallicities and radial velocities for more thanExpand
The multiplicity of the subgiant branch of ω centauri : Evidence for prolonged star formation
We combine spectroscopic and photometric data for subgiant stars of ω Cen to extract results that neither data set could have provided on its own. GIRAFFE@VLT spectra of 80 stars at R = 6400 giveExpand
The extended star formation history of ω Centauri
For the first time, the abundances of a large sample of subgiant and turn-off region stars in ω Centauri have been measured, the data base being medium resolution spectroscopy from FORS2 at the VLT.Expand
M54 + Sagittarius = ω Centauri
We derive homogeneous abundances of Fe, O, Na, and α-elements from high-resolution FLAMES spectra for 76 red giant stars in NGC 6715 (M54) and for 25 red giants in the surrounding nucleus of theExpand
A LARGE SAMPLE STUDY OF RED GIANTS IN THE GLOBULAR CLUSTER OMEGA CENTAURI (NGC 5139)
We present abundances of several light, α, Fe-peak, and neutron-capture elements for 66 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri (ω Cen). Our observations lie inExpand
Chemical composition of stellar populations in ω Centauri
Abstract We derive abundances of Fe, Na, O, α and s-elements from GIRAFFE@VLT spectra for more than 200 red giant stars in the Milky Way satellite ω Centauri. Our preliminary results are that: (i) weExpand
Fe and Al Abundances for 180 Red Giants in the Globular Cluster Omega Centauri (NGC 5139)
We present radial velocities and Fe and Al abundances for 180 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri (? Cen). The majority of our data lie in the range -->11.0 RExpand
CCD Photometry of the Globular Cluster ω Centauri. II. Stellar Populations and Age-Metallicity Relation
We present wide-field and high-precision BV and Ca and Stromgren by photometry of ω Centauri, which represents one of the most extensive photometric surveys to date for this cluster. The member starsExpand
First stars XII. Abundances in extremely metal-poor turnoff stars,and comparison with the giants
Context. The detailed chemical abundances of extremely metal-poor (EMP) stars are key guides to understanding the early chemical evolution of the Galaxy. Most existing data, however, treat giantExpand
CHEMICAL ABUNDANCES FOR 855 GIANTS IN THE GLOBULAR CLUSTER OMEGA CENTAURI (NGC 5139)
We present elemental abundances for 855 red giant branch (RGB) stars in the globular cluster Omega Centauri (ω Cen) from spectra obtained with the Blanco 4 m telescope and Hydra multifiberExpand
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2
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4
5
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