Gaia Data Release 2: Properties and validation of the radial velocities

D. Katz 1 P. Sartoretti 1 M. Cropper P. Panuzzo 2 G. M. Seabroke Y. Viala 1 K. Benson 3 R. Blomme 4 G. Jasniewicz 5 A. Jean-Antoine 6 H. Huckle M. Smith S. Baker F. Crifo 1 Y. Damerdji 7 M. David C. Dolding Y. Frémat 1 E. Gosset 8 A. Guerrier 6 L. P. Guy 9 R. Haigron 1 K. Janßen O. Marchal 10 G. Plum C. Soubiran 11 F. Thevenin 12 M. Ajaj C. Allende Prieto C. Babusiaux 1 S. Boudreault 13 L. Chemin C. Delle Luche 14 C. Fabre 15 A. Gueguen 16 N. C. Hambly Y. Lasne F. Meynadier 17 F. Pailler 18 C. Panem F. Royer 1 G. Tauran C. Zurbach 19 T. Zwitter F. Arenou 1 D. Bossini A. Gómez 20 V. Lemaitre N. Leclerc 21 T. Morel U. Munari C. Turon 1 A. Vallenari M. Žerjal
Abstract : For Gaia DR2 (GDR2), 280 million spectra, collected by the RVS instrument on-board Gaia, were processed and median radial velocities were derived for 9.8 million sources brighter than Grvs = 12 mag. This paper describes the validation and properties of the median radial velocities published in GDR2. Quality tests and filters are applied to select, from the 9.8 million radial velocities, those with the quality to be published in GDR2. The accuracy of the selected sample is assessed with respect to ground-based catalogues. Its precision is estimated using both ground-based catalogues and the distribution of the Gaia radial velocity uncertainties. GDR2 contains median radial velocities for 7 224 631 stars, with Teff in the range [3550, 6900] K, which passed succesfully the quality tests. The published median radial velocities provide a full sky-coverage and have a completness with respect to the astrometric data of 77.2\% (for $G \leq 12.5$ 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 100s m/s. In addition, the Gaia radial velocities show a positive trend as a function of magnitude, which starts around Grvs $\sim 9$ mag and reaches about $+500$ m/s at Grvs $= 11.75$ mag. The overall precision, estimated from the median of the Gaia radial velocity uncertainties, is 1.05 km/s. The radial velocity precision is function of many parameters, in particular the magnitude and effective temperature. For bright stars, Grvs in [4, 8] mag, the precision is in the range 200-350 m/s, which is about 3 to 5 times more precise than the pre-launch specification of 1 km/s. At the faint end, Grvs = 11.75 mag, the precisions for Teff = 5000 K and 6500 K are respectively 1.4 km/s and 3.7 km/s.
Type de document :
Article dans une revue
Astronomy and Astrophysics - A&A, EDP Sciences, 2018, pp.Submitted to A&A 2018
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-01868258
Contributeur : Marie-Paule Pomies <>
Soumis le : mercredi 5 septembre 2018 - 11:49:36
Dernière modification le : jeudi 13 décembre 2018 - 17:30:03

Lien texte intégral

Identifiants

Citation

D. Katz, P. Sartoretti, M. Cropper, P. Panuzzo, G. M. Seabroke, et al.. Gaia Data Release 2: Properties and validation of the radial velocities. Astronomy and Astrophysics - A&A, EDP Sciences, 2018, pp.Submitted to A&A 2018. 〈hal-01868258〉

Partager

Métriques

Consultations de la notice

205