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Author: Bragaglia, A. × End date: 2022 × Start date: 2022 × Type: Text × WGL Institute: AIP ×

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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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    Stellar Population Astrophysics (SPA) with the TNG: α-elements, lithium, sodium and aluminum in 16 open clusters
    (Les Ulis : EDP Sciences, 2022) Zhang, R.; Lucatello, S.; Bragaglia, A.; Alonso-Santiago, J.; Andreuzzi, G.; Casali, G.; Carrera, R.; Carretta, E.; D’Orazi, V.; Frasca, A.; Fu, X.; Magrini, L.; Minchev, I.; Origlia, L.; Spina, L.; Vallenari, A.
    Context. Exploring the Galactic chemical evolution and enrichment scenarios with open clusters (OCs) allows us to understand the history of the Milky Way disk. High-resolution spectra of OCs are a crucial tool, as they provide precise chemical information, to combine with precise distances and ages. Aims. The aim of the Stellar Population Astrophysics (SPA) project is to derive homogeneous and accurate comprehensive chemical characterization of a number of poorly studied OCs. Methods. Using the HARPS-N echelle spectrograph at the Telescopio Nazionale Galileo (TNG), we obtained high-resolution spectra of giant stars in 18 OCs, 16 of which are chemically characterized for the first time, and two of which are well studied for comparison. The OCs in this sample have ages from a few tens of Myr to 4 Gyr, with a prevalence of young clusters. We already presented the radial velocities and atmospheric parameters for them in a previous SPA paper. Here, we present results for the α-elements O, Mg, Si, Ca and Ti, and the light elements Na and Al, all determined by the equivalent width method. We also measured Li abundance through the synthesis method. Results. We discuss the behaviors of lithium, sodium and aluminum in the context of stellar evolution. For Na and Al, we compare our findings with models to investigate their behaviors as a function of mass, suggesting that Na mixing to the surface might start in masses as low as 2 M·. We study the radial, vertical, and age trends for the measured abundance ratios in a sample that combines our results and recent literature for OCs, finding significant (positive) gradients only for [Mg/Fe] and [Ca/Fe] in all cases. Finally, we compare O and Mg in the combined sample with chemo-dynamical models, finding a good agreement for intermediate-Age and old clusters. There is a sharp increase in the abundance ratios measured among very young clusters (age < 300 Myr), accompanied by a poorer fit with the models for O and Mg, likely related to the inadequacy of traditional model atmospheres and methods in the derivation of atmospheric parameters and abundance ratios for stars of such young ages.