1. The Gaia -ESO survey: Calibrating a relationship between age and the [C/N] abundance ratio with open clusters
- Author
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E. Tognelli, M. Van der Swaelmen, Gerry Gilmore, G. Casali, E. Pancino, Sofia Feltzing, Ulrike Heiter, Paula Jofre, A. Bragaglia, R. Bonito, Veronica Roccatagliata, Nicoletta Sanna, Simone Zaggia, F. M. Jiménez-Esteban, Maria Bergemann, Antonio Frasca, R. J. Jackson, Scilla Degl'Innocenti, Antonella Vallenari, Christian L. Sahlholdt, P. G. Prada Moroni, E. Franciosini, Thomas Bensby, Šarūnas Mikolaitis, Loredana Prisinzano, E. Stonkute, John D. Lewis, Y. Chorniy, V. Bagdonas, L. Morbidelli, Nadège Lagarde, G. Carraro, Arnas Drazdauskas, Sofia Randich, Grazina Tautvaisiene, A. C. Lanzafame, Lorenzo Spina, G. G. Sacco, Andreas Korn, S. G. Sousa, Rodolfo Smiljanic, S. L. Martell, Francesco Damiani, Thomas Masseron, Sergey E. Koposov, R. Minkeviciute, A. Hourihane, E. Friel, R. D. Jeffries, Amelia Bayo, Laura Magrini, C. C. Worley, G. Kordopatis, Anais Gonneau, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Keele University [Keele], Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Bologna (OABO), Lund Observatory, Lund University [Lund], Monash University [Clayton], INAF - Osservatorio Astronomico di Padova (OAPD), Department of Astronomy and Space Physics [Uppsala], Uppsala University, University of Turin, Istituto di Astrofisica Spaziale e Fisica cosmica - Palermo (IASF-Pa), INAF - Osservatorio Astrofisico di Catania (OACT), Gilmore, Gerard [0000-0003-4632-0213], Worley, Clare [0000-0001-9310-2898], and Apollo - University of Cambridge Repository
- Subjects
010504 meteorology & atmospheric sciences ,Metallicity ,astro-ph.GA ,Galaxy: abundances ,Galaxy: disk ,Open clusters and associations: general ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Astronomi, astrofysik och kosmologi ,Nucleosynthesis ,0103 physical sciences ,QB460 ,Astronomy, Astrophysics and Cosmology ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Physics ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Astrophysics::Instrumentation and Methods for Astrophysics ,abundances [Galaxy] ,Astronomy and Astrophysics ,Surface gravity ,Giant star ,Astrophysics - Astrophysics of Galaxies ,Red-giant branch ,Stars ,Star cluster ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,general [open clusters and associations] ,Astrophysics::Earth and Planetary Astrophysics ,disk [Galaxy] ,Open cluster ,QB799 - Abstract
In the era of large high-resolution spectroscopic surveys, high-quality spectra can contribute to our understanding of the Galactic chemical evolution, providing chemical abundances belonging to the different nucleosynthesis channels, and also providing constraints to stellar age. Some abundance ratios have been proven to be excellent indicators of stellar ages. We aim at providing an empirical relationship between stellar ages and [C/N] using, as calibrators, open star clusters observed by both the Gaia-ESO and APOGEE surveys. We use stellar parameters and abundances from the Gaia-ESO and APOGEE of the Galactic field and open cluster stars. Ages of star clusters are retrieved from the literature sources and validated using a common set of isochrones. We use the same isochrones to determine, for each age and metallicity, the surface gravity at which the first dredge-up and red giant branch bump occur. We study the effect of extra-mixing processes in our sample of giant stars, and we derive the mean [C/N] in evolved stars, including only stars without evidence of extra-mixing. Combining the Gaia-ESO and APOGEE samples of open clusters, we derive a linear relationship between [C/N] and logarithmic cluster ages. We apply our relationship to selected giant field stars in both Gaia-ESO and APOGEE. We find an age separation between thin and thick disc stars and age trends within their populations, with an increasing age towards lower metallicity populations. With such empirical relationship, we are able to provide an age estimate for giant stars in which C and N abundances are measured. Isochrone fitting is less sensitive for giant than dwarf stars at the turn off. The present method can be thus considered as an additional tool to give an independent estimate of the age of giant stars, with uncertainties in their ages comparable to those obtained using isochrone fitting for dwarf stars., Comment: 28 pages, 24 figures. Accepted by A&A
- Published
- 2019
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