Manganese Abundances in the Globular Cluster Omega Centauri

Abstract

We present manganese abundances in 10 red-giant members of the globular cluster Omega Centauri; 8 stars are from the most metal-poor population (RGB MP and RGB MInt1) while two targets are members of the more metal rich groups (RGB MInt2 and MInt3). This is the first time Mn abundances have been studied in this peculiar stellar system. The LTE values of [Mn/Fe] in Omega Cen overlap those of Milky Way stars in the metal poor Omega Cen populations ([Fe/H] ~ -1.5 to -1.8), however unlike what is observed in Milky Way halo and disk stars, [Mn/Fe] declines in the two more metal-rich RGB MInt2 and MInt3 targets. Non-LTE calculations were carried out in order to derive corrections to the LTE Mn abundances. The non-LTE results for Omega Cen in comparison with the non-LTE [Mn/Fe] versus [Fe/H] trend obtained for the Milky Way confirm and strengthen the conclusion that the manganese behavior in Omega Cen is distinct. These results suggest that low-metallicity supernovae (with metallicities < -2) of either Type II or Type Ia dominated the enrichment of the more metal-rich stars in Omega Cen. The dominance of low-metallicity stars in the chemical evolution of Omega Cen has been noted previously in the s-process elements where enrichment from metal-poor AGB stars is indicated. In addition, copper, which also has metallicity dependent yields, exhibits lower values of [Cu/Fe] in the RGB MInt2 and MInt3 Omega Cen populations.

Accepted for publication in the ApJ

References in corpus (15)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Oxygen, Sodium, Magnesium and Aluminium as tracers of the Galactic Bulge Formation
• NLTE abundances of Mn in a sample of metal-poor stars
• Chemical similarities between Galactic bulge and local thick disk red giant stars
• M 54 + Sagittarius = omega Centauri
• Chemical Evolution of the Galactic Bulge as Derived from High-Resolution Infrared Spectroscopy of K and M Red Giants
• Chemical abundances for 11 bulge stars from high-resolution, near-IR spectra
• The chemical evolution of Manganese in different stellar systems
• The End of Amnesia: A New Method for Measuring the Metallicity of Type Ia Supernova Progenitors Using Manganese Lines in Supernova Remnants
• Manganese Abundances in Cluster and Field Stars
• Manganese trends in a sample of thin and thick disk stars. The origin of Mn
• Contrasting copper evolution in Omega Centauri and the Milky Way
• Evidence of tidal debris from Omega Cen in the Kapteyn Group
• The chemical evolution of Omega Centauri's progenitor system
• Formation of MnI lines in the solar atmosphere

Cited by in corpus (12)

• Chemical Abundances for 855 Giants in the Globular Cluster Omega Centauri (NGC 5139)
• Chemistry of the Sagittarius Dwarf Galaxy: a Top-Light IMF, Outflows and the R-Process
• Two distinct halo populations in the solar neighborhood. II. Evidence from stellar abundances of Mn, Cu, Zn, Y, and Ba
• Manganese in dwarf spheroidal galaxies
• The Chemical Composition of the Galactic Bulge and Implications for its Evolution
• The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo
• Manganese Indicates a Transition from Sub- to Near-Chandrasekhar Type Ia Supernovae in Dwarf Galaxies
• Mn abundances in the stars of the Galactic disc with metallicities -1.0 < [Fe/H] < 0.3
• Light Element Discontinuities Suggest an Early Termination of Star Formation in the Globular Cluster NGC 6402 (M14)
• Manganese evolution in Omega Centauri: a clue to the cluster formation mechanisms?
• A new formation model for omega Centauri: the crossroad of astrophysical processes
• Galactic chemical evolution: the observational side