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Author: Bragaglia, A. × Author: Pancino, E. × End date: 2024 × Start date: 2020 × Version: publishedVersion ×

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    Gaia Early Data Release 3: The celestial reference frame (Gaia-CRF3)
    (Les Ulis : EDP Sciences, 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.
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    The Gaia -ESO Survey: Lithium measurements and new curves of growth
    (Les Ulis : EDP Sciences, 2022) Franciosini, E.; Randich, S.; de Laverny, P.; Biazzo, K.; Feuillet, D.K.; Frasca, A.; Lind, K.; Prisinzano, L.; Tautvaišiene, G.; Lanzafame, A.C.; Smiljanic, R.; Gonneau, A.; Magrini, L.; Pancino, E.; Guiglion, G.; Sacco, G.G.; Sanna, N.; Gilmore, G.; Bonifacio, P.; Jeffries, R.D.; Micela, G.; Prusti, T.; Alfaro, E.J.; Bensby, T.; Bragaglia, A.; François, P.; Korn, A.J.; Van Eck, S.; Bayo, A.; Bergemann, M.; Carraro, G.; Heiter, U.; Hourihane, A.; Jofré, P.; Lewis, J.; Martayan, C.; Monaco, L.; Morbidelli, L.; Worley, C.C.; Zaggia, S.
    Context. The Gaia-ESO Survey (GES) is a large public spectroscopic survey that was carried out using the multi-object FLAMES spectrograph at the Very Large Telescope. The survey provides accurate radial velocities, stellar parameters, and elemental abundances for ~115 000 stars in all Milky Way components. Aims. In this paper, we describe the method adopted in the final data release to derive lithium equivalent widths (EWs) and abundances. Methods. Lithium EWs were measured using two different approaches for FGK and M-type stars, to account for the intrinsic differences in the spectra. For FGK stars, we fitted the lithium line using Gaussian components, while direct integration over a predefined interval was adopted for M-type stars. Care was taken to ensure continuity between the two regimes. Abundances were derived using a new set of homogeneous curves of growth that were derived specifically for GES, and which were measured on a synthetic spectral grid consistently with the way the EWs were measured. The derived abundances were validated by comparison with those measured by other analysis groups using different methods. Results. Lithium EWs were measured for ~40 000 stars, and abundances could be derived for ~38 000 of them. The vast majority of the measures (80%) have been obtained for stars in open cluster fields. The remaining objects are stars in globular clusters, or field stars in the Milky Way disc, bulge, and halo. Conclusions. The GES dataset of homogeneous lithium abundances described here will be valuable for our understanding of several processes, from stellar evolution and internal mixing in stars at different evolutionary stages to Galactic evolution.
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    The Gaia-ESO survey: Mapping the shape and evolution of the radial abundance gradients with open clusters
    (Les Ulis : EDP Sciences, 2023) Magrini, L.; Viscasillas Vázquez, C.; Spina, L.; Randich, S.; Romano, D.; Franciosini, E.; Recio-Blanco, A.; Nordlander, T.; D'orazi, V.; Baratella, M.; Smiljanic, R.; Dantas, M.L.L.; Pasquini, L.; Spitoni, E.; Casali, G.; Van Der Swaelmen, M.; Bensby, T.; Stonkute, E.; Feltzing, S.; Sacco, G.G.; Bragaglia, A.; Pancino, E.; Heiter, U.; Biazzo, K.; Gilmore, G.; Bergemann, M.; Tautvaišienė, G.; Worley, C.; Hourihane, A.; Gonneau, A.; Morbidelli, L.
    Context. The spatial distribution of elemental abundances and their time evolution are among the major constraints to disentangling the scenarios of formation and evolution of the Galaxy. Aims. In this paper we used the sample of open clusters available in the final release of the Gaia-ESO survey to trace the Galactic radial abundance and abundance-to-iron ratio gradients, and their time evolution. Methods. We selected member stars in 62 open clusters, with ages from 0.1 to about 7 Gyr, located in the Galactic thin disc at galactocentric radii (RGC) from about 6 to 21 kpc. We analysed the shape of the resulting [Fe/H] gradient, the average gradients [El/H] and [El/Fe] combining elements belonging to four different nucleosynthesis channels, and their individual abundance and abundance ratio gradients. We also investigated the time evolution of the gradients dividing open clusters in three age bins. Results. The [Fe/H] gradient has a slope of −0.054 dex kpc−1. It can be better approximated with a two-slope shape, steeper for RGC ≤ 11.2 kpc and flatter in the outer regions. We saw different behaviours for elements belonging to different channels. For the time evolution of the gradient, we found that the youngest clusters (age < 1 Gyr) in the inner disc have lower metallicity than their older counterparts and that they outline a flatter gradient. We considered some possible explanations, including the effects of gas inflow and migration. We suggest that the most likely one may be related to a bias introduced by the standard spectroscopic analysis producing lower metallicities in the analysis of low-gravity stars. Conclusions. To delineate the shape of the ‘true’ gradient, we should most likely limit our analysis to stars with low surface gravity log g >  2.5 and microturbulent parameter ξ <  1.8 km s−1. Based on this reduced sample, we can conclude that the gradient has minimally evolved over the time-frame outlined by the open clusters, indicating a slow and stationary formation of the thin disc over the last 3 Gyr. We found a secondary role of cluster migration in shaping the gradient, with a more prominent role of migration for the oldest clusters.