RAVE Survey

The Radial Velocity Experiment

Wide-field spectroscopic surveys of the stellar content of the Galaxy provide crucial information on the combined chemical and dynamical history of the Milky Way, and for the understanding of the formation and evolution of galaxies in a broader context. Spectroscopy enables us to measure the radial velocities of stars, which, when combined with positions, distances, and proper motions from astrometry, allows us to study Galactic dynamics in detail. Spectroscopy also enables us to measure atmospheric properties (surface gravity and effective temperature) of stars and the abundance of chemical elements in the stellar atmosphere, thus providing important clues on the chemical evolution of the Galaxy and of its stellar populations. The combination of large wide-field spectroscopic surveys with massive and precise astrometric information as delivered by the Gaia mission is particular powerful. The scientific potential of combining wide-field spectroscopy and astrometry has been motivation for a number of spectroscopic Galactic Archaeology surveys, starting with the Geneva-Copenhagen (GCS) and the Radial Velocity Experiment RAVE presented here, followed by a meanwhile considerable number of surveys of similar or even larger size at lower (e.g., SEGUE and LAMOST) and higher spectral resolution (e.g., APOGEE, GALAH, and Gaia-ESO).

RAVE DR6

The Radial Velocity Experiment (RAVE) is a magnitude-limited (9 < I < 12) spectroscopic survey of Galactic stars randomly selected in the southern hemisphere. The Rave medium resolution spectra (R ˜ 7500) cover the Ca-triplet region (8410 - 8795 Å) and span the complete time frame from the start of RAVE observations on 12 April 2003 to their completion on 4 April 2013. Wavelength-calibrated and flux-normalized spectra for 518 387 observations of 451 783 unique stars are presented. The final data release 6 consists of spectra, error spectra, spectral classification, derived radial velocities, and cross matches with other relevant catalogs.

Further data products are using a suite of advanced reduction pipelines focussing on stellar atmospheric parameters, in particular purely spectroscopically derived stellar atmospheric parameters (T_eff, logx, and the overall metallicity), enhanced stellar parameters inferred via a Bayesian pipeline using Gaia DR2 astrometric priors, and asteroseismically calibrated stellar parametersfor giant stars based on asteroseismic observations for 699 K2 stars. In addition, we provide abundances of the elements Fe, Al, and Ni, as well as an overall [α/Fe] ratio obtained using a new pipeline based on the GAUGUIN optimization method that is able to deal with variable signal-to-noise ratios. The Rave DR6 catalogs are cross matched with relevant astrometric and photometric catalogs, and are complemented by orbital parameters and effective temperatures based on the infrared flux method.