Observed Stellar Spectra As Templates For Gaia

The goal of our survey is to provide accurate and multi-epoch radial velocities, atmospheric parameters (Teff , log g and [M/H]), distances, and space velocities of faint red clump stars. We recorded high signal-to-noise (S/N≥200) spectra of RC stars over the 4750-5950 Å range at a resolving power 5500. The target stars are distributed across the great circle of the celestial equator. Radial velocities were obtained via cross-correlation with IAU radial velocity standards. Atmospheric parameters were derived via χ2 fit to a synthetic spectral library. A large number of RC stars from other surveys were re-observed to check the consistency of our results and the absence of offsets and trends.
A total of 245 RC stars were observed (60 of them with a second epoch observation separated in time by about three months), and the results are presented in an output catalog. None of them is already present in other surveys of RC stars. In addition to astrometric and photometric support data from external sources, the catalog provides radial velocities (accuracy σ(RV)=1.3 km s⁻¹⁾, atmospheric parameters (σ(Teff)=88 K, σ(logg)=0.38 dex and σ([M/H])=0.17 dex), spectro-photometric distances, (X,Y,Z) galacto-centric positions and (U,V,W) space velocities.