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gaia early data release 3 documentation

9.3 External catalogues matched with Gaia EDR3

9.3.11 RAVE DR5

Reference paper:
Kunder et al. 2017

Original catalogue:

Data Release 5 (dr5) of the Radial Velocity Experiment (RAVE) is the fifth data release from a magnitude-limited (9<I<12) survey of stars randomly selected in the southern hemisphere. The RAVE medium-resolution spectra (R=7500) covering the Ca-triplet region (8410-8795 Å) span the complete time frame from the start of RAVE observations in 2003 to their completion in 2013. Radial velocities from 520 701 spectra of 457 588 unique stars are presented, of which 215 590 unique stars have parallaxes and proper motions from the Tycho-Gaia astrometric solution (TGAS) in Gaia DR1. For RAVE DR5 catalogue, stellar parameters (effective temperature, surface gravity, overall metallicity) are computed using the RAVE DR4 stellar pipeline, but calibrated using recent K2 Campaign 1 seismic gravities and Gaia benchmark stars, as well as results obtained from high-resolution studies. Also included are temperatures from the Infrared Flux Method, and it is provided a catalogue of red giant stars in the dereddened colour (J-Ks)0 interval (0.50, 0.85) for which the gravities were calibrated based only on seismology. Further data products for sub-samples of the RAVE stars include individual abundances for Mg, Al, Si, Ca, Ti, Fe, and Ni, and distances found using isochrones. This is the first RAVE data release in which an error spectrum was generated for each RAVE observations, so a realistic uncertainty and probability distribution functions for the derived radial velocities and stellar parameters are provided. The RAVE spectra were taken using the multi-object spectrograph 6dF (6 degree fields) on the 1.2 m UK Schmidt Telescope of the Australian Astronomical Observatory (AAO). Each fibre has a diameter of 100 μm (6.7′′ in the sky) and can be placed accurately (to within 10 μm, or 0.7′′) on star positions anywhere within the 6 diameter field.

Catalogue cleaning and Join table

In this work we used the RAVE DR5 v6 version of the RAVE catalogue. The catalogue has two identifiers: RAVEID (which is not unique in the catalogue and indicates a source) and RAVE_OBS_ID (which is unique in the catalogue and indicates different observations of a given source). However, there are a few thousand sources, with different RAVEIDs, that are close to each other and have very similar astrophysical parameters determinations. When a pair of sources is closer than 3′′ (i.e. less than half the fiber diameter), we consider them as suspected duplicates and use only one of them for cross-match calculations.

A convenience table is available that can be used to join RAVE DR5 catalogue with the cross-match results. The table links the external catalogue original sourceId ( original_ext_source_id), which is the RAVEID, to the corresponding additional numerical identifier ( clean_ravedr5_oid). Both original_ext_source_id and clean_ravedr5_oid are present in the cross-match output tables ( ravedr5_best_neighbour and ravedr5_neighbourhood). However, in case there are suspected duplicates in the external catalogue, different original_ext_source_id will correspond to the same clean_ravedr5_oid. In the cross-match output table only the original_ext_source_id of the source with the best astrometry among the suspected duplicates is listed. In practice, users may use the original_ext_source_id in the original catalogue to find the matching source with the best astrometry. Users interested to find all matching suspected duplicates should instead use the clean_ravedr5_oid in the join with the cross-match result tables.

Cross-match algorithm

According to the definition used in this work, RAVE DR5 is a sparse survey. In the cross-match algorithm RAVE DR5 is thus the leading catalogue, this means that counterparts for RAVE DR5 objects are searched for in Gaia. For this catalogue the special treatment to account for the small issues in Gaia astrometry, especially for bright stars, was applied.