Confirming chemical clocks: asteroseismic age dissection of the Milky Way disk(s)

Research output: Research - peer-reviewJournal article

  • V. Silva Aguirre
  • M. Bojsen-Hansen
    M. Bojsen-HansenStellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark.
  • D. Slumstrup
  • L. Casagrande
    L. CasagrandeResearch School of Astronomy and Astrophysics, Mount Stromlo Observatory, The Australian National University, ACT 2611, Australia 0000-0003-2688-7511
  • D. Kawata
    D. KawataMullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK
  • I. Ciucá
    I. CiucáMullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK
  • R. Handberg
  • M. N. Lund
  • J. R. Mosumgaard
  • D. Huber
    D. HuberInstitute for Astronomy, University of Hawaii, 2680 Wood- lawn Drive, Honolulu, HI 96822, USASydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, Sydney, NSW 2006, AustraliaStellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark.
  • J. A. Johnson
    J. A. JohnsonCenter for Cosmology and AstroParticle Physics, 191 West Woodruff Ave, Ohio State University, Columbus, OH 43210
  • M. H. Pinsonneault
    M. H. PinsonneaultDepartment of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210-1173, USA
  • A. M. Serenelli
    A. M. SerenelliInstituto de Ciencias del Espacio (ICE-CSIC/IEEC), Campus UAB, Carrer de Can Magrans, s/n, 08193 Cerdanyola del Valles, Spain 0000-0001-6359-2769
  • D. Stello
  • J. Tayar
    J. TayarDepartment of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210-1173, USA
  • J. C. Bird
    J. C. BirdDepartment of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Circle, Nashville, TN 37235, USA
  • S. Cassisi
    S. CassisiINAF-Astronomical Observatory of Teramo, Via M. Maggini sn, I-64100 Teramo, Italy
  • M. Hon
    M. HonSchool of Physics, University of New South Wales, NSW 2052, Australia 0000-0003-2400-6960
  • M. Martig
    M. MartigAstrophysics Research Institute, IC2, Liverpool Science Park, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF, UK
  • P. E. Nissen
  • H. W. Rix
    H. W. RixMax-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany
  • R. Schönrich
    R. SchönrichRudolf-Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, UK
  • C. Sahlholdt
    C. SahlholdtStellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark.
  • W. H. Trick
    W. H. TrickMax-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany
  • J. Yu
    J. YuSydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, Sydney, NSW 2006, AustraliaStellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark.
Investigations of the origin and evolution of the Milky Way disk have long relied on chemical and kinematic identification of its components to reconstruct our Galactic past. Difficulties in determining precise stellar ages have restricted most studies to small samples, normally confined to the solar neighbourhood. Here we break this impasse with the help of asteroseismic inference and perform a chronology of the evolution of the disk throughout the age of the Galaxy. We chemically dissect the Milky Way disk population using a sample of red giant stars spanning out to 2 kpc in the solar annulus observed by the Kepler satellite, with the added dimension of asteroseismic ages. Our results reveal a clear difference in age between the low- and high-α populations, which also show distinct velocity dispersions in the V and W components. We find no tight correlation between age and metallicity nor [α /Fe] for the high-α disk stars. Our results indicate that this component formed over a period of more than 2 Gyr with a wide range of [M/H] and [α /Fe] independent of time. Our findings show that the kinematic properties of young α-rich stars are consistent with the rest of the high-α population and different from the low-α stars of similar age, rendering support to their origin being old stars that went through a mass transfer or stellar merger event, making them appear younger, instead of migration of truly young stars formed close to the Galactic bar.
Original languageEnglish
JournalMonthly Notices of the Royal Astronomical Society, Advance Access
DOIs
StatePublished - 1 Jan 2018
Externally publishedYes

    Research areas

  • Galaxy: disc, Galaxy: evolution, Galaxy: structure, Asteroseismology, stars: fundamental parameters, stars: kinematics and dynamics

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ID: 120992316