Reference : Young [α/Fe]-enhanced stars discovered by CoRoT and APOGEE: What is their origin?
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/191922
Young [α/Fe]-enhanced stars discovered by CoRoT and APOGEE: What is their origin?
English
Chiappini, C. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482, Potsdam, Germany ; Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil]
Anders, F. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482, Potsdam, Germany; Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil]
Rodrigues, T. S. [Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil; Osservatorio Astronomico di Padova - INAF, Vicolo dell'Osservatorio 5, 35122, Padova, Italy; Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell'Osservatorio 3, 35122, Padova, Italy]
Miglio, A. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK]
Montalbán, J. [Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell'Osservatorio 3, 35122, Padova, Italy]
Mosser, B. [LESIA, Université Pierre et Marie Curie, Université Denis Diderot, Obs. de Paris, 92195, Meudon Cedex, France]
Girardi, L. [Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil; Osservatorio Astronomico di Padova - INAF, Vicolo dell'Osservatorio 5, 35122, Padova, Italy]
Valentini, M. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482, Potsdam, Germany]
Noels-Grötsch, Arlette mailto [Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO) >]
Morel, Thierry mailto [Université de Liège > > Groupe d'astrophysique des hautes énergies (GAPHE) >]
Minchev, I. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482, Potsdam, Germany]
Steinmetz, M. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482, Potsdam, Germany]
Santiago, B. X. [Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil; Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970, Porto Alegre, Brazil]
Schultheis, M. [Observatoire de la Côte d'Azur, Laboratoire Lagrange, CNRS UMR 7923, BP 4229, 06304, Nice Cedex, France]
Martig, M. [Max-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany]
da Costa, L. N. [Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil; Observatório Nacional, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil]
Maia, M. A. G. [Laboratório Interinstitucional de e-Astronomia, - LIneA, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil; Observatório Nacional, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil]
Allende Prieto, C. [Instituto de Astrofísica de Canarias, 38205, La Laguna, Tenerife, Spain; Universidad de La Laguna, Departamento de Astrofísica, 38206, La Laguna, Tenerife, Spain]
de Assis Peralta, R. [LESIA, Université Pierre et Marie Curie, Université Denis Diderot, Obs. de Paris, 92195, Meudon Cedex, France]
Hekker, S. [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077, Göttingen, Germany; Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000, Aarhus C, Denmark]
Themeßl, N. [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077, Göttingen, Germany; Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000, Aarhus C, Denmark]
Kallinger, T. [Institut für Astronomie, Universität Wien, Türkenschanzstr. 17, 1180, Wien, Austria]
García, R. A. [Laboratoire AIM, CEA/DSM - CNRS - Univ. Paris Diderot - IRFU/SAp, Centre de Saclay, 91191, Gif-sur-Yvette Cedex, France]
Mathur, S. [Space Science Institute, 4750 Walnut Street Suite 205, Boulder, CO, 80301, USA]
Baudin, F. [Institut dÁstrophysique Spatiale, UMR8617, CNRS, Université Paris XI, Bâtiment 121, 91405, Orsay Cedex, France]
Beers, T. C. [Dept. of Physics and JINA-CEE: Joint Institute for Nuclear Astrophysics - Center for the Evolution of the Elements, Univ. of Notre Dame, Notre Dame, IN, 46530, USA]
Cunha, K. [Observatório Nacional, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, Brazil]
Harding, P. [57 Department of Astronomy, Case Western Reserve University, Cleveland, OH, 44106, USA]
Holtzman, J. [New Mexico State University, Las Cruces, NM, 88003, USA]
Majewski, S. [Department of Astronomy, University of Virginia, PO Box 400325, Charlottesville, VA, 22904-4325, USA]
Mészáros, Sz [ELTE Gothard Astrophysical Observatory, 9704 Szombathely, Szent Imre herceg st., 112, Hungary; Department of Astronomy, Indiana University, Bloomington, IN, 47405, USA]
Nidever, D. [Dept. of Astronomy, University of Michigan, Ann Arbor, MI, 48104, USA]
Pan, K. [New Mexico State University, Las Cruces, NM, 88003, USA; Apache Point Observatory, PO Box 59, Sunspot, NM, 88349, USA]
Schiavon, R. P. [Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park 146, Brownlow Hill Liverpool, L3 5RF, UK]
Shetrone, M. D. [McDonald Observatory, University of Texas at Austin, HC75 Box 1337-MCD, Fort Davis, TX, 79734, USA]
Schneider, D. P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA, 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA, 16802, USA]
Stassun, K. [Vanderbilt University, Dept. of Physics & Astronomy, VU Station B 1807, Nashville, TN, 37235, USA)]
1-Apr-2015
Astronomy and Astrophysics
576
L12
Yes
International
[en] Galaxy: abundances ; Galaxy: disk ; Galaxy: formation ; Galaxy: stellar content ; stars: fundamental parameters ; asteroseismology
[en] We report the discovery of a group of apparently young CoRoT red-giant stars exhibiting enhanced [α/Fe] abundance ratios (as determined from APOGEE spectra) with respect to solar values. Their existence is not explained bystandard chemical evolution models of the Milky Way, and shows that the chemical-enrichment history of the Galactic disc is more complex. We find similar stars in previously published samples for which isochrone-ages could be reliably obtained, although in smaller relative numbers. This might explain why these stars have not previously received attention. The young [α/Fe]-rich stars are much more numerous in the CoRoT-APOGEE (CoRoGEE) inner-field sample than in any other high-resolution sample available at present because only CoRoGEE can explore the inner-disc regions and provide ages for its field stars. The kinematic properties of the young [α/Fe]-rich stars are not clearly thick-disc like, despite their rather large distances from the Galactic mid-plane. Our tentative interpretation of these and previous intriguing observations in the Milky Way is that these stars were formed close to the end of the Galactic bar, near corotation - a region where gas can be kept inert for longer times than in other regions that are more frequently shocked by the passage of spiral arms. Moreover, this is where the mass return from older inner-disc stellar generations is expected to be highest (according to an inside-out disc-formation scenario), which additionally dilutes the in-situ gas. Other possibilities to explain these observations (e.g., a recent gas-accretion event) are also discussed. Appendix A is available in electronic form at <A href="http://www.aanda.org/10.1051/0004-6361/201525865/olm">http://www.aanda.org</A>
http://hdl.handle.net/2268/191922
10.1051/0004-6361/201525865
http://adsabs.harvard.edu/abs/2015A%26A...576L..12C

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