A wide angle view of the Sagittarius dwarf spheroidal galaxy. II. A CEMP-r/s star in the Sagittarius dwarf spheroidal galaxy
Hansen, C. J.; Bonifacio, P.; Caffau, E.; Monaco, L.; Villanova, S.; Cristallo, S.; Sbordone, L.; Amigo, P.
Chile, Germany, Italy, France
Abstract
We report on the discovery and chemical abundance analysis of the first CEMP-r/s star detected in the Sagittarius dwarf spheroidal galaxy (Sgr dSph) by means of UVES high-resolution spectra. The star, found in the outskirts of Sgr dSph, along the major axis of the main body, is a moderately metal-poor giant (Teff = 4753 K, log g = 1.75, [Fe/H] = -1.55) with [C/Fe] = 1.13, placing it in the so-called "high-carbon band", and strong s-process and r-process enrichment ([Ba/Fe] = 1.4, [Eu/Fe] = 1.01). Abundances of 29 elements from C to Dy were obtained. The chemical pattern appears to be best fitted by a scenario where an r-process pollution event pre-enriched the material out of which the star was born as secondary in a binary system whose primary evolved through the AGB phase, providing C- and s-process enrichment.
Line-by-line abundance tables are are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/641/A135 Based on data collected with UVES at 8.2 m VLT-UT2 (Kueyen) telescope under ESO programme 083.B-0774. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.