Search Results
Gaia Data Release 2 : Properties and validation of the radial velocities
2019, Katz, D., Sartoretti, P., Cropper, M., Panuzzo, P., Seabroke, G.M., Viala, Y., Benson, K., Blomme, R., Jasniewicz, G., Jean-Antoine, A., Huckle, H., Smith, M., Baker, S., Crifo, F., Damerdji, Y., David, M., Dolding, C., Frémat, Y., Gosset, E., Guerrier, A., Guy, L. P., Haigron, R., Janßen, K., Marchal, O., Plum, G., Soubiran, C., Thévenin, F., Ajaj, M., Allende Prieto, C., Babusiaux, C., Boudreault, S., Chemin, L., Delle Luche, C., Fabre, C., Gueguen, A., Hambly, N. C., Lasne, Y., Meynadier, F., Pailler, F., Panem, C., Royer, F., Tauran, G., Zurbach, C., Zwitter, T., Arenou, F., Bossini, D., Gerssen, J., Gómez, A., Lemaitre, V., Leclerc, N., Morel, T., Munari, U., Turon, C., Vallenari, A., Žerjal, M.
Context. 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 2 [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.
Gaia Early Data Release 3: The celestial reference frame (Gaia-CRF3)
2022, Klioner, S.A., Lindegren, L., Mignard, F., Hernández, J., Ramos-Lerate, M., Bastian, U., Biermann, M., Bombrun, A., De Torres, A., Gerlach, E., Geyer, R., Fraile, E., Garabato, D., García-Lario, P., Gosset, E., Haigron, R., Halbwachs, J.-L., Hambly, N.C., Harrison, D.L., Hestroffer, D., Hodgkin, S.T., Hilger, T., Holl, B., Janben, K., Jevardat De Fombelle, G., Jordan, S., Krone-Martins, A., Lanzafame, A.C., Löffler, W., Marchal, O., Marrese, P.M., Moitinho, A., Hobbs, D., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Lammers, U.L., Sarro, L.M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., Van Leeuwen, M., Abbas, U., Ábrahám, P., Abreu Aramburu, A., Aerts, C., McMillan, P.J., Aguado, J.J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M.A., Alves, J., Anderson, R.I., Anglada Varela, E., Antoja, T., Baines, D., Steidelmüller, H., Baker, S.G., Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M.A., Bassilana, J.-L., Bauchet, N., Teyssier, D., Becciani, U., Bellazzini, M., Berihuete, A., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Boch, T., Bossini, D., Bouquillon, S., Raiteri, C.M., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A.G., Buzzi, R., Bartolomé, S., Caffau, E., Cancelliere, R., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M.I., Carrasco, J.M., Casamiquela, L., Castellani, M., Castro-Ginard, A., Bernet, M., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W.J., Cornez, T., Castañeda, J., Cowell, S., Crifo, F., Cropper, M., Crosta, M., Crowley, C., Dafonte, C., Dapergolas, A., David, P., De Laverny, P., De Luise, F., Clotet, M., De March, R., De Ridder, J., De Souza, R., Del Peloso, E.F., Del Pozo, E., Delbo, M., Delgado, A., Delisle, J.-B., Demouchy, C., Dharmawardena, T.E., Davidson, M., Diakite, S., Diener, C., Distefano, E., Dolding, C., Enke, H., Fabre, C., Fabrizio, M., Faigler, S., Fedorets, G., Fernique, P., Fabricius, C., Fienga, A., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., Garcia-Gutierrez, A., Garcia-Reinaldos, M., García-Torres, M., Garofalo, A., Garralda Torres, N., Gavel, A., Gavras, P., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., González-Vidal, J.J., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L.P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Portell, J., Sarmiento, M.H., Hidalgo, S.L., Hładczuk, N., Holland, G., Huckle, H.E., Jardine, K., Jasniewicz, G., Jean-Antoine Piccolo, A., Jiménez-Arranz, O., Juaristi Campillo, J., Rowell, N., Julbe, F., Karbevska, L., Kervella, P., Khanna, S., Kordopatis, G., Korn, A.J., Kóspál, A., Kostrzewa-Rutkowska, Z., Kruszyńska, K., Kun, M., Torra, F., Laizeau, P., Lambert, S., Lanza, A.F., Lasne, Y., Le Campion, J.-F., Lebreton, Y., Lebzelter, T., Leccia, S., Leclerc, N., Lecoeur-Taibi, I., Torra, J., Liao, S., Licata, E.L., Lindstrøm, H.E.P., Lister, T.A., Livanou, E., Lobel, A., Lorca, A., Loup, C., Madrero Pardo, P., Magdaleno Romeo, A., Brown, A.G.A., Managau, S., Mann, R.G., Manteiga, M., Marchant, J.M., Marconi, M., Marcos, J., Santos, M. M. S. Marcos, Marín Pina, D., Marinoni, S., Marocco, F., Vallenari, A., Marshall, D.J., Polo, L. Martin, Martín-Fleitas, J.M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., Messina, S., Prusti, T., Michalik, D., Millar, N.R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., De Bruijne, J.H.J., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Muraveva, T., Murphy, C.P., Musella, I., Nagy, Z., Noval, L., Arenou, F., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J.O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P.A., Pallas-Quintela, L., Panahi, A., Babusiaux, C., Payne-Wardenaar, S., Peñalosa Esteller, X., Penttilä, A., Pichon, B., Piersimoni, A.M., Pineau, F.-X., Plachy, E., Plum, G., Poggio, E., Prša, A., Creevey, O.L., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Rambaux, N., Ramos, P., Re Fiorentin, P., Regibo, S., Richards, P.J., Diaz, C. Rios, Ducourant, C., Ripepi, V., Riva, A., Rix, H.-W., Rixon, G., Robichon, N., Robin, A.C., Robin, C., Roelens, M., Rogues, H.R.O., Rohrbasser, L., Evans, D.W., Romero-Gómez, M., Royer, F., Ruz Mieres, D., Rybicki, K.A., Sadowski, G., Sáez Núñez, A., Sagristà Sellés, A., Sahlmann, J., Salguero, E., Samaras, N., Eyer, L., Sanchez Gimenez, V., Sanna, N., Santoveña, R., Sarasso, M., Schultheis, M., Sciacca, E., Segol, M., Segovia, J.C., Ségransan, D., Semeux, D., Guerra, R., Shahaf, S., Siddiqui, H.I., Siebert, A., Siltala, L., Silvelo, A., Slezak, E., Slezak, I., Smart, R.L., Snaith, O.N., Solano, E., Hutton, A., Solitro, F., Souami, D., Souchay, J., Spagna, A., Spina, L., Spoto, F., Steele, I.A., Stephenson, C.A., Süveges, M., Surdej, J., Jordi, C., Szabados, L., Szegedi-Elek, E., Taris, F., Taylor, M.B., Teixeira, R., Tolomei, L., Tonello, N., Torralba Elipe, G., Trabucchi, M., Tsounis, A.T., Luri, X., Turon, C., Ulla, A., Unger, N., Vaillant, M.V., Van Dillen, E., Van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Panem, C., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, L., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., Zucker, S., Zwitter, T., Pourbaix, D., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N.A., Bailer-Jones, C.A.L., Drimmel, R., Jansen, F., Katz, D., Lattanzi, M.G., Van Leeuwen, F., Bakker, J., Cacciari, C., De Angeli, F., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Mowlavi, N., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Roux, W., Seabroke, G.M., Sordo, R., Thévenin, F., Gracia-Abril, G., Altmann, M., Andrae, R., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P.W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Damerdji, Y., De Teodoro, P., Nuñez Campos, M., Delchambre, L., Dell'Oro, A., Esquej, P., Fernández-Hernández, J.
Context. Gaia-CRF3 is the celestial reference frame for positions and proper motions in the third release of data from the Gaia mission, Gaia DR3 (and for the early third release, Gaia EDR3, which contains identical astrometric results). The reference frame is defined by the positions and proper motions at epoch 2016.0 for a specific set of extragalactic sources in the (E)DR3 catalogue. Aims. We describe the construction of Gaia-CRF3 and its properties in terms of the distributions in magnitude, colour, and astrometric quality. Methods. Compact extragalactic sources in Gaia DR3 were identified by positional cross-matching with 17 external catalogues of quasi-stellar objects (QSO) and active galactic nuclei (AGN), followed by astrometric filtering designed to remove stellar contaminants. Selecting a clean sample was favoured over including a higher number of extragalactic sources. For the final sample, the random and systematic errors in the proper motions are analysed, as well as the radio-optical offsets in position for sources in the third realisation of the International Celestial Reference Frame (ICRF3). Results. Gaia-CRF3 comprises about 1.6 million QSO-like sources, of which 1.2 million have five-parameter astrometric solutions in Gaia DR3 and 0.4 million have six-parameter solutions. The sources span the magnitude range G = 13-21 with a peak density at 20.6 mag, at which the typical positional uncertainty is about 1 mas. The proper motions show systematic errors on the level of 12 μas yr-1 on angular scales greater than 15 deg. For the 3142 optical counterparts of ICRF3 sources in the S/X frequency bands, the median offset from the radio positions is about 0.5 mas, but it exceeds 4 mas in either coordinate for 127 sources. We outline the future of Gaia-CRF in the next Gaia data releases. Appendices give further details on the external catalogues used, how to extract information about the Gaia-CRF3 sources, potential (Galactic) confusion sources, and the estimation of the spin and orientation of an astrometric solution.