Gaia Early Data Release 3: Acceleration of the solar system from Gaia astrometry
Creators: name: Gaia Collaboration
name: Klioner, S. A.
name: Mignard, F.
name: Lindegren, L.
name: Bastian, U.
name: McMillan, P. J.
name: Hernández, J.
name: Hobbs, D.
name: Ramos-Lerate, M.
name: Biermann, M.
name: Bombrun, A.
name: de Torres, A.
name: Gerlach, E.
name: Geyer, R.
name: Hilger, T.
name: Lammers, U.
name: Steidelmüller, H.
name: Stephenson, C. A.
name: Brown, A. G. A.
name: Vallenari, A.
name: Prusti, T.
name: de Bruijne, J. H. J.
name: Babusiaux, C.
name: Creevey, O. L.
name: Evans, D. W.
name: Eyer, L.
name: Hutton, A.
name: Jansen, F.
name: Jordi, C.
name: Luri, X.
name: Panem, C.
name: Pourbaix, D.
name: Randich, S.
name: Sartoretti, P.
name: Soubiran, C.
name: Walton, N. A.
name: Arenou, F.
name: Bailer-Jones, C. A. L.
name: Cropper, M.
name: Drimmel, R.
name: Katz, D.
name: Lattanzi, M. G.
name: van Leeuwen, F.
name: Bakker, J.
name: Castañeda, J.
name: De Angeli, F.
name: Ducourant, C.
name: Fabricius, C.
name: Fouesneau, M.
name: Frémat, Y.
name: Guerra, R.
name: Guerrier, A.
name: Guiraud, J.
name: Piccolo, A. Jean-Antoine
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: Tanga, P.
name: Thévenin, F.
name: Gracia-Abril, G.
name: Portell, J.
name: Teyssier, D.
name: Altmann, M.
name: Andrae, R.
name: Bellas-Velidis, I.
name: Benson, K.
name: Berthier, J.
name: Blomme, R.
name: Brugaletta, E.
name: Burgess, P. W.
name: Busso, G.
name: Carry, B.
name: Cellino, A.
name: Cheek, N.
name: Clementini, G.
name: Damerdji, Y.
name: Davidson, M.
name: Delchambre, L.
name: Dell'Oro, A.
name: Fernández-Hernández, J.
name: Galluccio, L.
name: García-Lario, P.
name: Garcia-Reinaldos, M.
name: González-Núñez, J.
name: Gosset, E.
name: Haigron, R.
name: Halbwachs, J. -L.
name: Hambly, N. C.
name: Harrison, D. L.
name: Hatzidimitriou, D.
name: Heiter, U.
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: Lorca, A.
name: Manteiga, M.
name: Marchal, O.
name: Marrese, P. M.
name: Moitinho, A.
name: Mora, A.
name: Muinonen, K.
name: Osborne, P.
name: Pancino, E.
name: Pauwels, T.
name: Recio-Blanco, A.
name: Richards, P. J.
name: Riello, M.
name: Rimoldini, L.
name: Robin, A. C.
name: Roegiers, T.
name: Rybizki, J.
name: Sarro, L. M.
name: Siopis, C.
name: Smith, M.
name: Sozzetti, A.
name: Ulla, A.
name: Utrilla, E.
name: van Leeuwen, M.
name: van Reeven, W.
name: Abbas, U.
name: Aramburu, A. Abreu
name: Accart, S.
name: Aerts, C.
name: Aguado, J. J.
name: Ajaj, M.
name: Altavilla, G.
name: Álvarez, M. A.
name: Cid-Fuentes, J. Álvarez
name: Alves, J.
name: Anderson, R. I.
name: Varela, E. Anglada
name: Antoja, T.
name: Audard, M.
name: Baines, D.
name: Baker, S. G.
name: Balaguer-Nú\-nez, L.
name: Balbinot, E.
name: Balog, Z.
name: Barache, C.
name: Barbato, D.
name: Barros, M.
name: Barstow, M. A.
name: Bartolomé, S.
name: Bassilana, J. -L.
name: Bauchet, N.
name: Baudesson-Stella, A.
name: Becciani, U.
name: Bellazzini, M.
name: Bernet, M.
name: Bertone, S.
name: Bianchi, L.
name: Blanco-Cuaresma, S.
name: Boch, T.
name: Bossini, D.
name: Bouquillon, S.
name: Bramante, L.
name: Breedt, E.
name: Bressan, A.
name: Brouillet, N.
name: Bucciarelli, B.
name: Burlacu, A.
name: Busonero, D.
name: Butkevich, A. G.
name: Buzzi, R.
name: Caffau, E.
name: Cancelliere, R.
name: Cánovas, H.
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: Sampol, P. Castro
name: Chaoul, L.
name: Charlot, P.
name: Chemin, L.
name: Chiavassa, A.
name: Comoretto, G.
name: Cooper, W. J.
name: Cornez, T.
name: Cowell, S.
name: Crifo, F.
name: Crosta, M.
name: Crowley, C.
name: Dafonte, C.
name: Dapergolas, A.
name: David, M.
name: David, P.
name: de Laverny, P.
name: De Luise, F.
name: De March, R.
name: De Ridder, J.
name: de Souza, R.
name: de Teodoro, P.
name: del Peloso, E. F.
name: del Pozo, E.
name: Delgado, A.
name: Delgado, H. E.
name: Delisle, J. -B.
name: Di Matteo, P.
name: Diakite, S.
name: Diener, C.
name: Distefano, E.
name: Dolding, C.
name: Eappachen, D.
name: Enke, H.
name: Esquej, P.
name: Fabre, C.
name: Fabrizio, M.
name: Faigler, S.
name: Fedorets, G.
name: Fernique, P.
name: Fienga, A.
name: Figueras, F.
name: Fouron, C.
name: Fragkoudi, F.
name: Fraile, E.
name: Franke, F.
name: Gai, M.
name: Garabato, D.
name: Garcia-Gutierrez, A.
name: García-Torres, M.
name: Garofalo, A.
name: Gavras, P.
name: Giacobbe, P.
name: Gilmore, G.
name: Girona, S.
name: Giuffrida, G.
name: Gomez, A.
name: Gonzalez-Santamaria, I.
name: González-Vidal, J. J.
name: Granvik, M.
name: Gutiérrez-Sánchez, R.
name: Guy, L. P.
name: Hauser, M.
name: Haywood, M.
name: Helmi, A.
name: Hidalgo, S. L.
name: Hładczuk, N.
name: Holland, G.
name: Huckle, H. E.
name: Jasniewicz, G.
name: Jonker, P. G.
name: Campillo, J. Juaristi
name: Julbe, F.
name: Karbevska, L.
name: Kervella, P.
name: Khanna, S.
name: Kochoska, A.
name: Kordopatis, G.
name: Korn, A. J.
name: Kostrzewa-Rutkowska, Z.
name: Kruszyńska, K.
name: Lambert, S.
name: Lanza, A. F.
name: Lasne, Y.
name: Campion, J. -F. Le
name: Fustec, Y. Le
name: Lebreton, Y.
name: Lebzelter, T.
name: Leccia, S.
name: Leclerc, N.
name: Lecoeur-Taibi, I.
name: Liao, S.
name: Licata, E.
name: Lindstrøm, H. E. P.
name: Lister, T. A.
name: Livanou, E.
name: Lobel, A.
name: Pardo, P. Madrero
name: Managau, S.
name: Mann, R. G.
name: Marchant, J. M.
name: Marconi, M.
name: Santos, M. M. S. Marcos
name: Marinoni, S.
name: Marocco, F.
name: Marshall, D. J.
name: Polo, L. Martin
name: Martín-Fleitas, J. M.
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: Montegriffo, P.
name: Mor, R.
name: Morbidelli, R.
name: Morel, T.
name: Morris, D.
name: Mulone, A. F.
name: Munoz, D.
name: Muraveva, T.
name: Murphy, C. P.
name: Musella, I.
name: Noval, L.
name: Ordénovic, C.
name: Orrù, G.
name: Osinde, J.
name: Pagani, C.
name: Pagano, I.
name: Palaversa, L.
name: Palicio, P. A.
name: Panahi, A.
name: Pawlak, M.
name: Esteller, X. Pe\-nalosa
name: Penttilä, A.
name: Piersimoni, A. M.
name: Pineau, F. -X.
name: Plachy, E.
name: Plum, G.
name: Poggio, E.
name: Poretti, E.
name: Poujoulet, E.
name: Prša, A.
name: Pulone, L.
name: Racero, E.
name: Ragaini, S.
name: Rainer, M.
name: Raiteri, C. M.
name: Rambaux, N.
name: Ramos, P.
name: Fiorentin, P. Re
name: Regibo, S.
name: Reylé, C.
name: Ripepi, V.
name: Riva, A.
name: Rixon, G.
name: Robichon, N.
name: Robin, C.
name: Roelens, M.
name: Rohrbasser, L.
name: Romero-Gómez, M.
name: Rowell, N.
name: Royer, F.
name: Rybicki, K. A.
name: Sadowski, G.
name: Sellés, A. Sagristà
name: Sahlmann, J.
name: Salgado, 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: Siddiqui, H. I.
name: Siebert, A.
name: Siltala, L.
name: Slezak, E.
name: Smart, R. L.
name: Solano, E.
name: Solitro, F.
name: Souami, D.
name: Souchay, J.
name: Spagna, A.
name: Spoto, F.
name: Steele, I. A.
name: Süveges, M.
name: Szabados, L.
name: Szegedi-Elek, E.
name: Taris, F.
name: Tauran, G.
name: Taylor, M. B.
name: Teixeira, R.
name: Thuillot, W.
name: Tonello, N.
name: Torra, F.
name: Torray, J.
name: Turon, C.
name: Unger, N.
name: Vaillant, M.
name: van Dillen, E.
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: Zurbach, C.
name: Zwitter, T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Context. Gaia Early Data Release 3 (Gaia EDR3) provides accurate astrometry for about 1.6 million compact (QSO-like) extragalactic sources, 1.2 million of which have the best-quality five-parameter astrometric solutions. Aims. The proper motions of QSO-like sources are used to reveal a systematic pattern due to the acceleration of the solar system barycentre with respect to the rest frame of the Universe. Apart from being an important scientific result by itself, the acceleration measured in this way is a good quality indicator of the Gaia astrometric solution. Methods. The effect of the acceleration is obtained as a part of the general expansion of the vector field of proper motions in Vector Spherical Harmonics (VSH). Various versions of the VSH fit and various subsets of the sources are tried and compared to get the most consistent result and a realistic estimate of its uncertainty. Additional tests with the Gaia astrometric solution are used to get a better idea on possible systematic errors in the estimate. Results. Our best estimate of the acceleration based on Gaia EDR3 is $(2.32 \pm 0.16) \times 10^{-10}$ m s${}^{-2}$ (or $7.33 \pm 0.51$ km s$^{-1}$ Myr${}^{-1}$) towards $α= 269.1^\circ \pm 5.4^\circ$, $δ= -31.6^\circ \pm 4.1^\circ$, corresponding to a proper motion amplitude of $5.05 \pm 0.35$ $μ$as yr${}^{-1}$. This is in good agreement with the acceleration expected from current models of the Galactic gravitational potential. We expect that future Gaia data releases will provide estimates of the acceleration with uncertainties substantially below 0.1 $μ$as yr${}^{-1}$.
description: A&amp;A, accepted