SIMBAD references

Based on the medium-high resolution (R ∼ 20,000), modest signal-to-noise ratio (S/N >= 70) FLAMES-GIRAFFE spectra, we investigated the copper abundances of 129 red giant branch stars in the Galactic bulge with [Fe/H] from -1.14 to 0.46 dex. The copper abundances are derived from both local thermodynamic equilibrium (LTE) and nonlocal thermodynamic equilibrium (NLTE) with the spectral synthesis method. We find that the NLTE effects for Cu I lines show a clear dependence on metallicity, and they gradually increase with decreasing [Fe/H] for our sample stars. Our results indicate that the NLTE effects of copper are important not only for metal-poor stars but also for supersolar metal-rich ones and the LTE results underestimate the Cu abundances. We note that the [Cu/Fe] trend of the bulge stars is similar to that of the Galactic disk stars spanning the metallicity range of -1.14 < [Fe/H] < 0.0 dex, and the [Cu/Fe] ratios increase with increasing metallicity when [Fe/H] is from ∼-1.2 to ∼-0.5 dex, favoring a secondary (metallicity-dependent) production of Cu.