Mean PASTEL atmospheric parameters

The investigated surveys are the latest public releases of APOGEE, GALAH, RAVE, LAMOST, SEGUE, and the Gaia-ESO Survey. We use reference samples that provide independent determinations of [Fe/H], which are compared to those from the surveys for common stars. The distribution of the residuals is assessed through simple statistics that measure the offset between two catalogues and the dispersion representative of the precision of both catalogues.

When relevant, linear fits are performed. A large sample of FGK-type stars with [Fe/H] based on high-resolution, high-signal-to-noise spectroscopy was built from the PASTEL catalogue to provide a reference sample. We also use FGK members in open and globular clusters to assess the internal consistency of [Fe/H] of each survey.

The agreement of median [Fe/H] values for clusters observed by different surveys is discussed. All the surveys overestimate the low metallicities, and some of them also underestimate the high metallicities. They perform well in the most populated intermediate metallicity range whatever the resolution.

In most cases, the typical precision that we deduce from the comparisons is in good agreement with the uncertainties quoted in the catalogues. Some exceptions to this general behaviour are discussed.