Gaia Early Data Release 3: The celestial reference frame (Gaia-CRF3)
Creators: name: Gaia Collaboration
name: Klioner, S. A.
name: Lindegren, L.
name: Mignard, F.
name: Hernández, J.
name: Ramos-Lerate, M.
name: Bastian, U.
name: Biermann, M.
name: Bombrun, A.
name: de Torres, A.
name: Gerlach, E.
name: Geyer, R.
name: Hilger, T.
name: Hobbs, D.
name: Lammers, U. L.
name: McMillan, P. J.
name: Steidelmüller, H.
name: Teyssier, D.
name: Raiteri, C. M.
name: Bartolomé, S.
name: Bernet, M.
name: Castañeda, J.
name: Clotet, M.
name: Davidson, M.
name: Fabricius, C.
name: Torres, N. Garralda
name: González-Vidal, J. J.
name: Portell, J.
name: Rowell, N.
name: Torra, F.
name: Torra, J.
name: Brown, A. G. A.
name: Vallenari, A.
name: Prusti, T.
name: de Bruijne, J. H. J.
name: Arenou, F.
name: Babusiaux, C.
name: Creevey, O. L.
name: Ducourant, C.
name: Evans, D. W.
name: Eyer, L.
name: Guerra, R.
name: Hutton, A.
name: Jordi, C.
name: Luri, X.
name: Panem, C.
name: Pourbaix, D.
name: Randich, S.
name: Sartoretti, P.
name: Soubiran, C.
name: Tanga, P.
name: Walton, N. A.
name: Bailer-Jones, C. A. L.
name: Drimmel, R.
name: Jansen, F.
name: Katz, D.
name: Lattanzi, M. G.
name: van Leeuwen, F.
name: Bakker, J.
name: Cacciari, C.
name: De Angeli, F.
name: Fouesneau, M.
name: Frémat, Y.
name: Galluccio, L.
name: Guerrier, A.
name: Heiter, U.
name: Masana, E.
name: Messineo, R.
name: Mowlavi, N.
name: Nicolas, C.
name: Nienartowicz, K.
name: Pailler, F.
name: Panuzzo, P.
name: Riclet, F.
name: Roux, W.
name: Seabroke, G. M.
name: Sordo, R.
name: Thévenin, F.
name: Gracia-Abril, G.
name: Altmann, M.
name: Andrae, R.
name: Audard, M.
name: Bellas-Velidis, I.
name: Benson, K.
name: Berthier, J.
name: Blomme, R.
name: Burgess, P. W.
name: Busonero, D.
name: Busso, G.
name: Cánovas, H.
name: Carry, B.
name: Cellino, A.
name: Cheek, N.
name: Clementini, G.
name: Damerdji, Y.
name: de Teodoro, P.
name: Campos, M. Nuñez
name: Delchambre, L.
name: Dell'Oro, A.
name: Esquej, P.
name: Fernández-Hernández, J.
name: Fraile, E.
name: Garabato, D.
name: García-Lario, P.
name: Gosset, E.
name: Haigron, R.
name: Halbwachs, J. -L.
name: Hambly, N. C.
name: Harrison, D. L.
name: Hestroffer, D.
name: Hodgkin, S. T.
name: Holl, B.
name: Janßen, K.
name: de Fombelle, G. Jevardat
name: Jordan, S.
name: Krone-Martins, A.
name: Lanzafame, A. C.
name: Löffler, W.
name: Marchal, O.
name: Marrese, P. M.
name: Moitinho, A.
name: Muinonen, K.
name: Osborne, P.
name: Pancino, E.
name: Pauwels, T.
name: Recio-Blanco, A.
name: Reylé, C.
name: Riello, M.
name: Rimoldini, L.
name: Roegiers, T.
name: Rybizki, J.
name: Sarro, L. M.
name: Siopis, C.
name: Smith, M.
name: Sozzetti, A.
name: Utrilla, E.
name: van Leeuwen, M.
name: Abbas, U.
name: Ábrahám, P.
name: Aramburu, A. Abreu
name: Aerts, C.
name: Aguado, J. J.
name: Ajaj, M.
name: Aldea-Montero, F.
name: Altavilla, G.
name: Álvarez, M. A.
name: Alves, J.
name: Anderson, R. I.
name: Varela, E. Anglada
name: Antoja, T.
name: Baines, D.
name: Baker, S. G.
name: Balaguer-Núñez, L.
name: Balbinot, E.
name: Balog, Z.
name: Barache, C.
name: Barbato, D.
name: Barros, M.
name: Barstow, M. A.
name: Bassilana, J. -L.
name: Bauchet, N.
name: Becciani, U.
name: Bellazzini, M.
name: Berihuete, A.
name: Bertone, S.
name: Bianchi, L.
name: Binnenfeld, A.
name: Blanco-Cuaresma, S.
name: Boch, T.
name: Bossini, D.
name: Bouquillon, S.
name: Bragaglia, A.
name: Bramante, L.
name: Breedt, E.
name: Bressan, A.
name: Brouillet, N.
name: Brugaletta, E.
name: Bucciarelli, B.
name: Burlacu, A.
name: Butkevich, A. G.
name: Buzzi, R.
name: Caffau, E.
name: Cancelliere, R.
name: Cantat-Gaudin, T.
name: Carballo, R.
name: Carlucci, T.
name: Carnerero, M. I.
name: Carrasco, J. M.
name: Casamiquela, L.
name: Castellani, M.
name: Castro-Ginard, A.
name: Chaoul, L.
name: Charlot, P.
name: Chemin, L.
name: Chiaramida, V.
name: Chiavassa, A.
name: Chornay, N.
name: Comoretto, G.
name: Contursi, G.
name: Cooper, W. J.
name: Cornez, T.
name: Cowell, S.
name: Crifo, F.
name: Cropper, M.
name: Crosta, M.
name: Crowley, C.
name: Dafonte, C.
name: Dapergolas, A.
name: David, P.
name: de Laverny, P.
name: De Luise, F.
name: De March, R.
name: De Ridder, J.
name: de Souza, R.
name: del Peloso, E. F.
name: del Pozo, E.
name: Delbo, M.
name: Delgado, A.
name: Delisle, J. -B.
name: Demouchy, C.
name: Dharmawardena, T. E.
name: Diakite, S.
name: Diener, C.
name: Distefano, E.
name: Dolding, C.
name: Enke, H.
name: Fabre, C.
name: Fabrizio, M.
name: Faigler, S.
name: Fedorets, G.
name: Fernique, P.
name: Fienga, A.
name: Figueras, F.
name: Fournier, Y.
name: Fouron, C.
name: Fragkoudi, F.
name: Gai, M.
name: Garcia-Gutierrez, A.
name: Garcia-Reinaldos, M.
name: García-Torres, M.
name: Garofalo, A.
name: Gavel, A.
name: Gavras, P.
name: Giacobbe, P.
name: Gilmore, G.
name: Girona, S.
name: Giuffrida, G.
name: Gomel, R.
name: Gomez, A.
name: González-Núñez, J.
name: González-Santamaría, I.
name: Granvik, M.
name: Guillout, P.
name: Guiraud, J.
name: Gutiérrez-Sánchez, R.
name: Guy, L. P.
name: Hatzidimitriou, D.
name: Hauser, M.
name: Haywood, M.
name: Helmer, A.
name: Helmi, A.
name: Sarmiento, M. H.
name: Hidalgo, S. L.
name: Hładczuk, N.
name: Holland, G.
name: Huckle, H. E.
name: Jardine, K.
name: Jasniewicz, G.
name: Piccolo, A. Jean-Antoine
name: Jiménez-Arranz, Ó.
name: Campillo, J. Juaristi
name: Julbe, F.
name: Karbevska, L.
name: Kervella, P.
name: Khanna, S.
name: Kordopatis, G.
name: Korn, A. J.
name: Kóspál, Á
name: Kostrzewa-Rutkowska, Z.
name: Kruszyńska, K.
name: Kun, M.
name: Laizeau, P.
name: Lambert, S.
name: Lanza, A. F.
name: Lasne, Y.
name: Campion, J. -F. Le
name: Lebreton, Y.
name: Lebzelter, T.
name: Leccia, S.
name: Leclerc, N.
name: Lecoeur-Taibi, I.
name: Liao, S.
name: Licata, E. L.
name: Lindstrøm, H. E. P.
name: Lister, T. A.
name: Livanou, E.
name: Lobel, A.
name: Lorca, A.
name: Loup, C.
name: Pardo, P. Madrero
name: Romeo, A. Magdaleno
name: Managau, S.
name: Mann, R. G.
name: Manteiga, M.
name: Marchant, J. M.
name: Marconi, M.
name: Marcos, J.
name: Santos, M. M. S. Marcos
name: Pina, D. Marín
name: Marinoni, S.
name: Marocco, F.
name: Marshall, D. J.
name: Polo, L. Martin
name: Martín-Fleitas, J. M.
name: Marton, G.
name: Mary, N.
name: Masip, A.
name: Massari, D.
name: Mastrobuono-Battisti, A.
name: Mazeh, T.
name: Messina, S.
name: Michalik, D.
name: Millar, N. R.
name: Mints, A.
name: Molina, D.
name: Molinaro, R.
name: Molnár, L.
name: Monari, G.
name: Monguió, M.
name: Montegriffo, P.
name: Montero, A.
name: Mor, R.
name: Mora, A.
name: Morbidelli, R.
name: Morel, T.
name: Morris, D.
name: Muraveva, T.
name: Murphy, C. P.
name: Musella, I.
name: Nagy, Z.
name: Noval, L.
name: Ocaña, F.
name: Ogden, A.
name: Ordenovic, C.
name: Osinde, J. O.
name: Pagani, C.
name: Pagano, I.
name: Palaversa, L.
name: Palicio, P. A.
name: Pallas-Quintela, L.
name: Panahi, A.
name: Payne-Wardenaar, S.
name: Esteller, X. Peñalosa
name: Penttilä, A.
name: Pichon, B.
name: Piersimoni, A. M.
name: Pineau, F. -X.
name: Plachy, E.
name: Plum, G.
name: Poggio, E.
name: Prša, A.
name: Pulone, L.
name: Racero, E.
name: Ragaini, S.
name: Rainer, M.
name: Rambaux, N.
name: Ramos, P.
name: Fiorentin, P. Re
name: Regibo, S.
name: Richards, P. J.
name: Diaz, C. Rios
name: Ripepi, V.
name: Riva, A.
name: Rix, H. -W.
name: Rixon, G.
name: Robichon, N.
name: Robin, A. C.
name: Robin, C.
name: Roelens, M.
name: Rogues, H. R. O.
name: Rohrbasser, L.
name: Romero-Gómez, M.
name: Royer, F.
name: Mieres, D. Ruz
name: Rybicki, K. A.
name: Sadowski, G.
name: Núñez, A. Sáez
name: Sellés, A. Sagristà
name: Sahlmann, J.
name: Salguero, E.
name: Samaras, N.
name: Gimenez, V. Sanchez
name: Sanna, N.
name: Santoveña, R.
name: Sarasso, M.
name: Schultheis, M.
name: Sciacca, E.
name: Segol, M.
name: Segovia, J. C.
name: Ségransan, D.
name: Semeux, D.
name: Shahaf, S.
name: Siddiqui, H. I.
name: Siebert, A.
name: Siltala, L.
name: Silvelo, A.
name: Slezak, E.
name: Slezak, I.
name: Smart, R. L.
name: Snaith, O. N.
name: Solano, E.
name: Solitro, F.
name: Souami, D.
name: Souchay, J.
name: Spagna, A.
name: Spina, L.
name: Spoto, F.
name: Steele, I. A.
name: Stephenson, C. A.
name: Süveges, M.
name: Surdej, J.
name: Szabados, L.
name: Szegedi-Elek, E.
name: Taris, F.
name: Taylor, M. B.
name: Teixeira, R.
name: Tolomei, L.
name: Tonello, N.
name: Elipe, G. Torralba
name: Trabucchi, M.
name: Tsounis, A. T.
name: Turon, C.
name: Ulla, A.
name: Unger, N.
name: Vaillant, M. V.
name: van Dillen, E.
name: van Reeven, W.
name: Vanel, O.
name: Vecchiato, A.
name: Viala, Y.
name: Vicente, D.
name: Voutsinas, S.
name: Weiler, M.
name: Wevers, T.
name: Wyrzykowski, Ł.
name: Yoldas, A.
name: Yvard, P.
name: Zhao, H.
name: Zorec, J.
name: Zucker, S.
name: Zwitter, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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. We describe the construction of Gaia-CRF3, and its properties in terms of the distributions in magnitude, colour, and astrometric quality. Compact extragalactic sources in Gaia DR3 were identified by positional cross-matching with 17 external catalogues of quasars (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). The 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 to 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 $μ$as 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 exceeds 4 mas in either coordinate for 127 sources. We outline the future of the Gaia-CRF in the next Gaia data releases.