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Author: Schultheis, M. × Publisher: Les Ulis : EDP Sciences ×

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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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    Cool stars in the Galactic center as seen by APOGEE : M giants, AGB stars, and supergiant stars and candidates
    (Les Ulis : EDP Sciences, 2020) Schultheis, M.; Rojas-Arriagada, A.; Cunha, K.; Zoccali, M.; Chiappini, C.; Zasowski, G.; Queiroz, A.B.A.; Minniti, D.; Fritz, T.; García-Hernández, D.A.; Nitschelm, C.; Zamora, O.; Hasselquist, S.; Fernández-Trincado, J.G.; Munoz, R.R.
    The Galactic center region, including the nuclear disk, has until recently been largely avoided in chemical census studies because of extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), allow the measurement of metallicities in the inner region of our Galaxy. Making use of the latest APOGEE data release (DR16), we are able for the first time to study cool Asymptotic Giant branch (AGB) stars and supergiants in this region. The stellar parameters of five known AGB stars and one supergiant star (VR 5-7) show that their location is well above the tip of the red giant branch. We studied metallicities of 157 M giants situated within 150 pc of the Galactic center from observations obtained by the APOGEE survey with reliable stellar parameters from the APOGEE pipeline making use of the cool star grid down to 3200 K. Distances, interstellar extinction values, and radial velocities were checked to confirm that these stars are indeed situated in the Galactic center region. We detect a clear bimodal structure in the metallicity distribution function, with a dominant metal-rich peak of [Fe/H] ∼ +0.3 dex and a metal-poor peak around {Fe/H] = −0.5 dex, which is 0.2 dex poorer than Baade’s Window. The α-elements Mg, Si, Ca, and O show a similar trend to the Galactic bulge. The metal-poor component is enhanced in the α-elements, suggesting that this population could be associated with the classical bulge and a fast formation scenario. We find a clear signature of a rotating nuclear stellar disk and a significant fraction of high-velocity stars with vgal >  300 km s−1; the metal-rich stars show a much higher rotation velocity (∼200 km s−1) with respect to the metal-poor stars (∼140 km s−1). The chemical abundances as well as the metallicity distribution function suggest that the nuclear stellar disk and the nuclear star cluster show distinct chemical signatures and might be formed differently.