Title: | Gaia Data Release 2. Mapping the Milky Way disc kinematics |
Authors: | Gaia Collaboration Katz, D. Antoja, T. Romero-Gómez, M. DRIMMEL, Ronald Reylé, C. Seabroke, G. M. Soubiran, C. Babusiaux, C. Di Matteo, P. Figueras, F. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J. M. Casamiquela, L. CASTELLANI, Marco Castro-Ginard, A. Charlot, P. Chemin, L. Biermann, M. Krone-Martins, A. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. CROSTA, Mariateresa Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Lanzafame, Alessandro Carmelo Eyer, L. Dapergolas, A. David, P. David, M. de Laverny, P. DE LUISE, Fiore De March, R. de Souza, R. de Torres, A. Debosscher, J. Lebzelter, T. del Pozo, E. Jansen, F. Delbo, M. Delgado, A. Delgado, H. E. Diakite, S. Diener, C. DISTEFANO, Elisa Maria Carmela Dolding, C. Drazinos, P. Löffler, W. Durán, J. Edvardsson, B. Jordi, C. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. FABRIZIO, Michele Faigler, S. Manteiga, M. Falc a, A. J. Farràs Casas, M. Federici, L. Klioner, S. A. Fedorets, G. Fernique, P. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. MARRESE, Paola Maria Fraser, M. Frézouls, B. GAI, Mario GALLETI, SILVIA Lammers, U. Garabato, D. García-Sedano, F. GAROFALO, Alessia Garralda, N. Gavel, A. Martín-Fleitas, J. M. Gavras, P. Gerssen, J. Geyer, R. GIACOBBE, Paolo Gilmore, G. Lindegren, L. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Moitinho, A. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutié, R. Haigron, R. Luri, X. Hatzidimitriou, D. Hauser, M. Haywood, M. Mora, A. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Mignard, F. Huckle, H. E. Hypki, A. Muinonen, K. Icardi, V. Janßen, K. Jevardat de Fombelle, G. Jonker, P. G. Juhász, Á. L. Julbe, F. Karampelas, A. Kewley, A. Panem, C. Klar, J. Poggio, Eloisa Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S. E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Pourbaix, D. Osinde, J. Lambert, S. LANZA, Antonino Francesco Lasne, Y. Lavigne, J. -B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. LECCIA, Silvio Leclerc, N. Lecoeur-Taibi, I. PANCINO, ELENA RANDICH, Maria Sofia Lenhardt, H. Leroux, F. Liao, S. LICATA, ENRICO Lindstrøm, H. E. P. Lister, T. A. Livanou, E. Lobel, A. López, M. Pauwels, T. Managau, S. Sartoretti, P. Mann, R. G. Mantelet, G. Marchal, O. Marchant, J. M. MARCONI, Marcella MARINONI, SILVIA Marschalkó, G. Marshall, D. J. Petit, J. -M. Martino, M. Marton, G. Siddiqui, H. I. Mary, N. Massari, D. Matijevič, G. Mazeh, T. McMillan, P. J. MESSINA, Sergio Michalik, D. Recio-Blanco, A. Millar, N. R. Molina, D. MOLINARO, Roberto van Leeuwen, F. Molnár, L. MONTEGRIFFO, Paolo Mor, R. MORBIDELLI, Roberto Morel, T. Morris, D. Richards, P. J. Mulone, A. F. Muraveva, Tatiana MUSELLA, ILARIA Nelemans, G. Walton, N. A. NICASTRO, LUCIANO Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Rimoldini, L. Osborne, P. Pagani, C. PAGANO, Isabella Pailler, F. Palacin, H. Arenou, F. Palaversa, L. Panahi, A. Pawlak, M. PIERSIMONI, Anna Marina Sarro, L. M. Pineau, F. -X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. PULONE, Luigi Bastian, U. Racero, E. Ragaini, S. Rambaux, N. Siopis, C. Ramos-Lerate, M. Regibo, S. Riclet, F. RIPEPI, Vincenzo RIVA, Alberto Rivard, A. Rixon, G. Cropper, M. Roegiers, T. Roelens, M. Smith, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. LATTANZI, Mario Gilberto SANNA, Nicoletta Robin, A. C. Santana-Ros, T. SARASSO, Maria Margherita Savietto, H. Schultheis, M. SCIACCA, Eva Segol, M. Segovia, J. C. Ségransan, D. Shih, I. -C. Bakker, J. SOZZETTI, Alessandro Siltala, L. Silva, A. F. SMART, Richard Laurence Smith, K. W. Solano, E. Solitro, F. SORDO, ROSANNA Soria Nieto, S. Souchay, J. SPAGNA, Alessandro Süveges, M. Cacciari, C. Spoto, F. Stampa, U. Steele, I. A. Steidelmüller, H. Stephenson, C. A. Stoev, H. Suess, F. F. Surdej, J. Szabados, L. Torra, J. Szegedi-Elek, E. Casta n, J. Tapiador, D. Taris, F. Tauran, G. Taylor, M. B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. van Reeven, W. Titarenko, A. Torra Clotet, F. Chaoul, L. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. VALENTINI, Gaetano Valette, V. ABBAS, Ummi van Elteren, A. Van Hemelryck, E. van Leeuwen, M. Cheek, N. Vaschetto, M. VECCHIATO, Alberto Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Abreu Aramburu, A. von Essen, C. Voss, H. Votruba, V. Voutsinas, S. De Angeli, F. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Accart, S. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Fabricius, C. Zucker, S. Zurbach, C. Zwitter, T. Guerra, R. Aerts, C. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Tanga, P. Thévenin, F. ALTAVILLA, GIUSEPPE Gracia-Abril, G. COMORETTO, Giovanni Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Álvarez, M. A. Blomme, R. Burgess, P. Busso, G. Carry, B. CELLINO, Alberto CLEMENTINI, Gisella Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Evans, D. W. Delchambre, L. DELL'ORO, Aldo Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J. J. Alvarez, R. Gosset, E. Guy, L. P. Halbwachs, J. -L. Hambly, N. C. Harrison, D. L. Hernández, J. Hestroffer, D. Hodgkin, S. T. Hutton, A. Jasniewicz, G. Alves, J. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A. J. Anderson, R. I. Andrei, A. H. Anglada Varela, E. Antiche, E. Arcay, B. Astraatmadja, T. L. Bach, N. Baker, S. G. Brown, A. G. A. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P. S. Barrado, D. Barros, M. Barstow, M. A. VALLENARI, Antonella Bartholomé Muñoz, L. Bassilana, J. -L. BECCIANI, Ugo BELLAZZINI, Michele Berihuete, A. BERTONE, Stefano Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Prusti, T. BOECHE, CORRADO Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. BRAGAGLIA, Angela Bramante, L. Breddels, M. A. Bressan, A. de Bruijne, J. H. J. Brouillet, N. Brüsemeister, T. Brugaletta, Elisa BUCCIARELLI, Beatrice Burlacu, A. BUSONERO, Deborah Butkevich, A. G. BUZZI, RAFFAELLA Caffau, E. Cancelliere, R. Bailer-Jones, C. A. L. Cannizzaro, G. |
Issue Date: | 2018 |
Journal: | ASTRONOMY & ASTROPHYSICS |
Number: | 616 |
First Page: | A11 |
Abstract: | Context. The second Gaia data release (Gaia DR2) contains high-precision positions, parallaxes, and proper motions for 1.3 billion sources as well as line-of-sight velocities for 7.2 million stars brighter than G<SUB>RVS</SUB> = 12 mag. Both samples provide a full sky coverage. <BR /> Aims: To illustrate the potential of Gaia DR2, we provide a first look at the kinematics of the Milky Way disc, within a radius of several kiloparsecs around the Sun. <BR /> Methods: We benefit for the first time from a sample of 6.4 million F-G-K stars with full 6D phase-space coordinates, precise parallaxes (σ<SUB>ϖ</SUB>/ϖ ≤ 20%), and precise Galactic cylindrical velocities (median uncertainties of 0.9-1.4 km s<SUP>-1</SUP> and 20% of the stars with uncertainties smaller than 1 km s<SUP>-1</SUP> on all three components). From this sample, we extracted a sub-sample of 3.2 million giant stars to map the velocity field of the Galactic disc from 5 kpc to 13 kpc from the Galactic centre and up to 2 kpc above and below the plane. We also study the distribution of 0.3 million solar neighbourhood stars (r < 200 pc), with median velocity uncertainties of 0.4 km s<SUP>-1</SUP>, in velocity space and use the full sample to examine how the over-densities evolve in more distant regions. <BR /> Results: Gaia DR2 allows us to draw 3D maps of the Galactocentric median velocities and velocity dispersions with unprecedented accuracy, precision, and spatial resolution. The maps show the complexity and richness of the velocity field of the galactic disc. We observe streaming motions in all the components of the velocities as well as patterns in the velocity dispersions. For example, we confirm the previously reported negative and positive galactocentric radial velocity gradients in the inner and outer disc, respectively. Here, we see them as part of a non-axisymmetric kinematic oscillation, and we map its azimuthal and vertical behaviour. We also witness a new global arrangement of stars in the velocity plane of the solar neighbourhood and in distant regions in which stars are organised in thin substructures with the shape of circular arches that are oriented approximately along the horizontal direction in the U - V plane. Moreover, in distant regions, we see variations in the velocity substructures more clearly than ever before, in particular, variations in the velocity of the Hercules stream. <BR /> Conclusions: Gaia DR2 provides the largest existing full 6D phase-space coordinates catalogue. It also vastly increases the number of available distances and transverse velocities with respect to Gaia DR1. Gaia DR2 offers a great wealth of information on the Milky Way and reveals clear non-axisymmetric kinematic signatures within the Galactic disc, for instance. It is now up to the astronomical community to explore its full potential. |
URI: | http://hdl.handle.net/20.500.12386/28221 |
URL: | http://arxiv.org/abs/1804.09380v1 https://www.aanda.org/articles/aa/abs/2018/08/aa32865-18/aa32865-18.html |
ISSN: | 0004-6361 |
DOI: | 10.1051/0004-6361/201832865 |
Bibcode ADS: | 2018A&A...616A..11G |
Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista
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