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Your search keyword '"Núñez, J. González"' showing total 4 results
Start Over Author "Núñez, J. González" Topic astrophysics::cosmology and extragalactic astrophysics
4 results on '"Núñez, J. González"'

1. Gaia Data Release 2: Variable stars in the colour-absolute magnitude diagram

Author

Eyer, L. Rimoldini, L. Audard, M. Anderson, R.I. Nienartowicz, K. Glass, F. Marchal, O. Grenon, M. Mowlavi, N. Holl, B. Clementini, G. Aerts, C. Mazeh, T. Evans, D.W. Szabados, L. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Bailer-Jones, C.A.L. Biermann, M. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Van Leeuwen, F. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Masana, E. Messineo, R. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. 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. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. Jevardat De Fombelle, G. Jonker, P.G. Juhász, A.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Lorenz, D. Managau, S. Mann, R.G. Mantelet, G. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijevič, G. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, A. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G ≲ 21 mag. Aims. We showcase stellar variability in the Galactic colour-absolute magnitude diagram (CaMD). We focus on pulsating, eruptive, and cataclysmic variables, as well as on stars that exhibit variability that is due to rotation and eclipses. Methods. We describe the locations of variable star classes, variable object fractions, and typical variability amplitudes throughout the CaMD and show how variability-related changes in colour and brightness induce "motions". To do this, we use 22 months of calibrated photometric, spectro-photometric, and astrometric Gaia data of stars with a significant parallax. To ensure that a large variety of variable star classes populate the CaMD, we crossmatched Gaia sources with known variable stars. We also used the statistics and variability detection modules of the Gaia variability pipeline. Corrections for interstellar extinction are not implemented in this article. Results. Gaia enables the first investigation of Galactic variable star populations in the CaMD on a similar, if not larger, scale as was previously done in the Magellanic Clouds. Although the observed colours are not corrected for reddening, distinct regions are visible in which variable stars occur. We determine variable star fractions to within the current detection thresholds of Gaia. Finally, we report the most complete description of variability-induced motion within the CaMD to date. Conclusions. Gaia enables novel insights into variability phenomena for an unprecedented number of stars, which will benefit the understanding of stellar astrophysics. The CaMD of Galactic variable stars provides crucial information on physical origins of variability in a way that has previously only been accessible for Galactic star clusters or external galaxies. Future Gaia data releases will enable significant improvements over this preview by providing longer time series, more accurate astrometry, and additional data types (time series BP and RP spectra, RVS spectra, and radial velocities), all for much larger samples of stars. © 2019 ESO.

Published
2019

2. Observational hertzsprung-russell diagrams

Author

Babusiaux, C. Van Leeuwen, F. Barstow, M.A. Jordi, C. Vallenari, A. Bossini, D. Bressan, A. Cantat-Gaudin, T. Van Leeuwen, M. Brown, A.G.A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. 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. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypersy, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. De Fombelle, G.J. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijević, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Context. Gaia Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. The precision, accuracy, and homogeneity of both astrometry and photometry are unprecedented. Aims. We highlight the power of the Gaia DR2 in studying many fine structures of the Hertzsprung-Russell diagram (HRD). Gaia allows us to present many different HRDs, depending in particular on stellar population selections. We do not aim here for completeness in terms of types of stars or stellar evolutionary aspects. Instead, we have chosen several illustrative examples. Methods. We describe some of the selections that can be made in Gaia DR2 to highlight the main structures of the Gaia HRDs. We select both field and cluster (open and globular) stars, compare the observations with previous classifications and with stellar evolutionary tracks, and we present variations of the Gaia HRD with age, metallicity, and kinematics. Late stages of stellar evolution such as hot subdwarfs, post-AGB stars, planetary nebulae, and white dwarfs are also analysed, as well as low-mass brown dwarf objects. Results. The Gaia HRDs are unprecedented in both precision and coverage of the various Milky Way stellar populations and stellar evolutionary phases. Many fine structures of the HRDs are presented. The clear split of the white dwarf sequence into hydrogen and helium white dwarfs is presented for the first time in an HRD. The relation between kinematics and the HRD is nicely illustrated. Two different populations in a classical kinematic selection of the halo are unambiguously identified in the HRD. Membership and mean parameters for a selected list of open clusters are provided. They allow drawing very detailed cluster sequences, highlighting fine structures, and providing extremely precise empirical isochrones that will lead to more insight in stellar physics. Conclusions. Gaia DR2 demonstrates the potential of combining precise astrometry and photometry for large samples for studies in stellar evolution and stellar population and opens an entire new area for HRD-based studies. © ESO 2018.

Published
2018

3. Gaia Data Release 2: The celestial reference frame (Gaia -CRF2)

Author

Mignard, F. Klioner, S.A. Lindegren, L. Hernández, J. Bastian, U. Bombrun, A. Hobbs, D. Lammers, U. Michalik, D. Ramos-Lerate, M. Biermann, M. Fernández-Hernández, J. Geyer, R. Hilger, T. Siddiqui, H.I. Steidelmüller, H. Babusiaux, C. Barache, C. Lambert, S. Andrei, A.H. Bourda, G. Charlot, P. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Luri, X. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Soubiran, C. Van Leeuwen, F. Walton, N.A. Arenou, F. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Borrachero, R. Bossini, D. Bouquillon, S. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. DIakite, S. DIener, C. DIstefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. Jevardat De Fombelle, G. Jonker, P.G. Juhász, A.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, L. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Context. The second release of Gaia data (Gaia DR2) contains the astrometric parameters for more than half a million quasars. This set defines a kinematically non-rotating reference frame in the optical domain. A subset of these quasars have accurate VLBI positions that allow the axes of the reference frame to be aligned with the International Celestial Reference System (ICRF) radio frame. Aims. We describe the astrometric and photometric properties of the quasars that were selected to represent the celestial reference frame of Gaia DR2 (Gaia-CRF2), and to compare the optical and radio positions for sources with accurate VLBI positions. Methods. Descriptive statistics are used to characterise the overall properties of the quasar sample. Residual rotation and orientation errors and large-scale systematics are quantified by means of expansions in vector spherical harmonics. Positional differences are calculated relative to a prototype version of the forthcoming ICRF3. Results. Gaia-CRF2 consists of the positions of a sample of 556 869 sources in Gaia DR2, obtained from a positional cross-match with the ICRF3-prototype and AllWISE AGN catalogues. The sample constitutes a clean, dense, and homogeneous set of extragalactic point sources in the magnitude range G ≈ 16 to 21 mag with accurately known optical positions. The median positional uncertainty is 0.12 mas for G < 18 mag and 0.5 mas at G = mag. Large-scale systematics are estimated to be in the range 20 to 30 μas. The accuracy claims are supported by the parallaxes and proper motions of the quasars in Gaia DR2. The optical positions for a subset of 2820 sources in common with the ICRF3-prototype show very good overall agreement with the radio positions, but several tens of sources have significantly discrepant positions. Conclusions. Based on less than 40% of the data expected from the nominal Gaia mission, Gaia-CRF2 is the first realisation of a non-rotating global optical reference frame that meets the ICRS prescriptions, meaning that it is built only on extragalactic sources. Its accuracy matches the current radio frame of the ICRF, but the density of sources in all parts of the sky is much higher, except along the Galactic equator. © ESO 2018.

Published
2018

4. Mapping the milky way disc kinematics

Author

Katz, D. Antoja, T. Romero-Gómez, M. Drimmel, R. Reylé, C. Seabroke, G.M. Soubiran, C. Babusiaux, C. Di Matteo, P. Figueras, F. Poggio, E. Robin, A.C. Evans, D.W. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Biermann, M. Eyer, L. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Van Leeuwen, F. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. 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. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypersy, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. De Fombelle, G.J. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijević, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.

Subjects
Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
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 GRVS = 12 mag. Both samples provide a full sky coverage. 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. 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 (σω/ω/≤ 20%), and precise Galactic cylindrical velocities (median uncertainties of 0.9-1.4 km s-1 and 20% of the stars with uncertainties smaller than 1 km s-1 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-1, in velocity space and use the full sample to examine how the over-densities evolve in more distant regions. 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. 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. © ESO 2018.

Published
2018

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