Gaia FGK benchmark stars: abundances of α and iron-peak elements
P. Jofré, U. Heiter, C. Soubiran, S. Blanco-Cuaresma, T. Masseron, T. Nordlander, L. Chemin, C. Worley, S. Van Eck, A. Hourihane, G. Gilmore, V. Zh. Adibekyan, M. Bergemann, T. Cantat-Gaudin, E. Delgado Mena, J. I. González Hernández, G. Guiglion, C. Lardo, P. de Laverny, K. Lind, L. Magrini, S. Mikolaitis, D. Montes, E. Pancino, A. Recio-Blanco, R. Sordo, S. G. Sousa, H. M. Tabernero, A. Vallenari
Aims. We determine elemental abundances of Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Co, and Ni for our predefined set of Gaia FGK benchmark stars.
Methods. By analysing high-resolution spectra with a high signal-to-noise ratio taken from several archive datasets, we combined results of eight different methods to determine abundances on a line-by-line basis. We performed a detailed homogeneous analysis of the systematic uncertainties, such as differential versus absolute abundance analysis. We also assessed errors that are due to non-local thermal equilibrium and the stellar parameters in our final abundances.
Results. Our results are provided by listing final abundances and the different sources of uncertainties, as well as line-by-line and method-by-method abundances.
Conclusions. The atmospheric parameters of the Gaia FGK benchmark stars are already being widely used for calibration of several pipelines that are applied to different surveys. With the added reference abundances of ten elements, this set is very suitable for calibrating the chemical abundances obtained by these pipelines.
Astronomy and Astrophysics