000004586 001__ 4586
000004586 005__ 20200120180321.0
000004586 0247_ $$2DOI$$a10.1051/0004-6361/201833273
000004586 037__ $$aSCART-2020-0026
000004586 100__ $$aKatz, D.
000004586 245__ $$aGaia Data Release 2. Properties and validation of the radial velocities
000004586 260__ $$c2019
000004586 520__ $$aContext. For Gaia DR2, 280 million spectra collected by the Radial Velocity Spectrometer instrument on board Gaia were processed, and median radial velocities were derived for 9.8 million sources brighter than GRVS = 12 mag. Aims: This paper describes the validation and properties of the median radial velocities published in Gaia DR2. Methods: Quality tests and filters were applied to select those of the 9.8 million radial velocities that have the quality to be published in Gaia DR2. The accuracy of the selected sample was assessed with respect to ground-based catalogues. Its precision was estimated using both ground-based catalogues and the distribution of the Gaia radial velocity uncertainties. Results: Gaia DR2 contains median radial velocities for 7 224 631 stars, with Teff in the range [3550, 6900] K, which successfully passed the quality tests. The published median radial velocities provide a full-sky coverage and are complete with respect to the astrometric data to within 77.2% (for G ≤ 12.5 mag). The median radial velocity residuals with respect to the ground-based surveys vary from one catalogue to another, but do not exceed a few 100 m s-1. In addition, the Gaia radial velocities show a positive trend as a function of magnitude, which starts around GRVS 9 mag and reaches about + 500 m s-1 at GRVS = 11.75 mag. The origin of the trend is under investigation, with the aim to correct for it in Gaia DR3. The overall precision, estimated from the median of the Gaia radial velocity uncertainties, is 1.05 km s-1. The radial velocity precision is a function of many parameters, in particular, the magnitude and effective temperature. For bright stars, GRVS ∈ [4, 8] mag, the precision, estimated using the full dataset, is in the range 220-350 m s-1, which is about three to five times more precise than the pre-launch specification of 1 km s-1. At the faint end, GRVS = 11.75 mag, the precisions for Teff = 5000 and 6500 K are 1.4 and 3.7 km s-1, respectively. 
000004586 536__ $$aGaia Prodex project/$$cGaia Prodex project/$$fGaia Prodex project
000004586 594__ $$aNO
000004586 6531_ $$atechniques: spectroscopic
000004586 6531_ $$atechniques: radial velocities
000004586 6531_ $$acatalogs
000004586 6531_ $$asurveys
000004586 700__ $$aSartoretti, P.
000004586 700__ $$aCropper, M.
000004586 700__ $$aPanuzzo, P.
000004586 700__ $$aSeabroke, G. M.
000004586 700__ $$aViala, Y.
000004586 700__ $$aBenson, K.
000004586 700__ $$aBlomme, R.
000004586 700__ $$aJasniewicz, G.
000004586 700__ $$aJean-Antoine, A.
000004586 700__ $$aHuckle, H.
000004586 700__ $$aSmith, M.
000004586 700__ $$aBaker, S.
000004586 700__ $$aCrifo, F.
000004586 700__ $$aDamerdji, Y.
000004586 700__ $$aDavid, M.
000004586 700__ $$aDolding, C.
000004586 700__ $$aFrémat, Y.
000004586 700__ $$aGosset, E.
000004586 700__ $$aGuerrier, A.
000004586 700__ $$aGuy, L. P.
000004586 700__ $$aHaigron, R.
000004586 700__ $$aJanßen, K.
000004586 700__ $$aMarchal, O.
000004586 700__ $$aPlum, G.
000004586 700__ $$aSoubiran, C.
000004586 700__ $$aThévenin, F.
000004586 700__ $$aAjaj, M.
000004586 700__ $$aAllende Prieto, C.
000004586 700__ $$aBabusiaux, C.
000004586 700__ $$aBoudreault, S.
000004586 700__ $$aChemin, L.
000004586 700__ $$aDelle Luche, C.
000004586 700__ $$aFabre, C.
000004586 700__ $$aGueguen, A.
000004586 700__ $$aHambly, N. C.
000004586 700__ $$aLasne, Y.
000004586 700__ $$aMeynadier, F.
000004586 700__ $$aPailler, F.
000004586 700__ $$aPanem, C.
000004586 700__ $$aRoyer, F.
000004586 700__ $$aTauran, G.
000004586 700__ $$aZurbach, C.
000004586 700__ $$aZwitter, T.
000004586 700__ $$aArenou, F.
000004586 700__ $$aBossini, D.
000004586 700__ $$aGerssen, J.
000004586 700__ $$aGómez, A.
000004586 700__ $$aLemaitre, V.
000004586 700__ $$aLeclerc, N.
000004586 700__ $$aMorel, T.
000004586 700__ $$aMunari, U.
000004586 700__ $$aTuron, C.
000004586 700__ $$aVallenari, A.
000004586 700__ $$aŽerjal, M.
000004586 773__ $$cA205, 19 pp.$$pAstronomy & Astrophysics$$v622$$y2019
000004586 8560_ $$fronny.blomme@observatoire.be
000004586 85642 $$ahttps://ui.adsabs.harvard.edu/abs/2019A%26A...622A.205K/abstract
000004586 905__ $$apublished in
000004586 980__ $$aREFERD