The catalogue of radial velocity standard stars for Gaia: I. Pre-launch release

The Radial Velocity Spectrograph (RVS) on board Gaia needs to be calibrated using stable reference stars known in advance. The catalogue presented here was built for that purpose. It includes 1420 radial velocity standard star candidates selected on strict criteria to fulfill the Gaia-RVS requirements. A large programme of ground-based observations has been underway since 2006 to monitor these stars and verify their stability, which has to be better than 300 m s[sup -1] over several years. Three hundred forty-three stars are found to be constant at the level of 100 m s[sup -1] over 10 years. Comparisons with earlier catalogues show excellent agreement for FGK stars, with zero-point differences lower than 100 m s[sup -1] and a remarkably low rms scatter of 33 m s[sup -1] in one case, suggesting that the precision of the catalogue presented here is better than this value. This catalogue will likely be useful for other large-scale spectroscopic surveys, such as APOGEE, Gaia-ESO, HERMES, and LAMOST.