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

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal article

  • V. Silva Aguirre
  • M. Bojsen-Hansen,
  • D. Slumstrup
  • L. Casagrande, Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, The Australian National University, ACT 2611, Australia 0000-0003-2688-7511, D. Kawata, Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK, I. Ciucǎ, Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK,
  • R. Handberg
  • M. N. Lund
  • J. R. Mosumgaard
  • D. Huber, Institute for Astronomy, University of Hawaii, 2680 Wood- lawn Drive, Honolulu, HI 96822, USA, Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, Sydney, NSW 2006, Australia, J. A. Johnson, Center for Cosmology and AstroParticle Physics, 191 West Woodruff Ave, Ohio State University, Columbus, OH 43210, USA, M. H. Pinsonneault, Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA, A. M. Serenelli, Instituto 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, Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA, J. C. Bird, Department of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Circle, Nashville, TN 37235, USA, S. Cassisi, INAF-Osservatorio Astronomico di Teramo, via M. Maggini, I-64100 Teramo, Italy, M. Hon, School of Physics, University of New South Wales, NSW 2052, Australia 0000-0003-2400-6960, M. Martig, Astrophysics Research Institute, IC2, Liverpool Science Park, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF, UK,
  • P. E. Nissen
  • H. W. Rix, Max-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany, R. Schönrich, Rudolf-Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, UK, C. Sahlholdt, W. H. Trick, Max-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany,
  • J. Yu
Investigations of the origin and evolution of the Milky Way disc have long relied on chemical and kinematic identifications 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 disc throughout the age of the Galaxy. We chemically dissect the Milky Way disc 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 disc 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
Volume475
Issue number4
Pages (from-to)5487-5500
ISSN0035-8711
DOIs
StatePublished - 1 Apr 2018

    Research areas

  • asteroseismology, stars: fundamental parameters, stars: kinematics and dynamic, Galaxy: disc, Galaxy: evolution, Galaxy: structure

See relations at Aarhus University Citationformats

ID: 124873205