Correlations between age, kinematics, and chemistry as seen by the RAVE survey

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Abstract

We explore the connections between stellar age, chemistry, and kinematics across a Galactocentric distance of 7.5 < R(kpc) < 9.0, using a sample of ~12 000 intermediate-mass (FGK) turn-offstars observed with the RAdial Velocity Experiment (RAVE) survey. The kinematics of this sample are determined using radial velocity measurements from RAVE, and parallax and proper motion measurements from the Tycho-Gaia Astrometric Solution (TGAS). In addition, ages for RAVE stars are determined using a Bayesian method, taking TGAS parallaxes as a prior. We divide our sample into young (0 < τ < 3 Gyr) and old (8 < τ < 13 Gyr) populations, and then consider different metallicity bins for each of these age groups. We find significant differences in kinematic trends of young and old, metal-poor and metal-rich, stellar populations. In particular, we find a strong metallicity dependence in the mean Galactocentric radial velocity as a function of radius (∂V R /∂R) for young stars, with metal-rich stars having a much steeper gradient than metal-poor stars. For ∂V Φ /∂R, young, metal-rich stars significantly lag the LSR with a slightly positive gradient, while metal-poor stars show a negative gradient above the LSR. We interpret these findings as correlations between metallicity and the relative contributions of the non-axisymmetries in the Galactic gravitational potential (the spiral arms and the bar) to perturb stellar orbits.

Detaljer

Författare
  • Jennifer Wojno
  • Georges Kordopatis
  • Matthias Steinmetz
  • James Binney
  • Benoit Famaey
  • Giacomo Monari
  • Ivan Minchev
  • Rosemary F.G. Wyse
  • Teresa Antoja
  • Arnaud Siebert
  • Ismael Carrillo
  • Joss Bland-Hawthorn
  • Eva K. Grebel
  • Tomaž Zwitter
  • Olivier Bienaymé
  • Brad Gibson
  • Andrea Kunder
  • Ulisse Munari
  • Julio Navarro
  • Quentin Parker
  • Warren Reid
  • George Seabroke
Enheter & grupper
Externa organisationer
  • Leibniz Institute for Astrophysics Potsdam (AIP)
  • Johns Hopkins University
  • Côte d'Azur Observatory
  • University of Oxford
  • University of Strasbourg
  • University of Barcelona
  • University of Sydney
  • Heidelberg University
  • University of Ljubljana
  • University of Hull
  • Saint Martin's University
  • INAF - Osservatorio Astronomico di Padova
  • University of Victoria
  • University of Hong Kong
  • Macquarie University, Sydney
  • Western Sydney University
  • University College London
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Astronomi, astrofysik och kosmologi

Nyckelord

Originalspråkengelska
Sidor (från-till)5612-5624
Antal sidor13
TidskriftMonthly Notices of the Royal Astronomical Society
Volym477
Utgåva nummer4
StatusPublished - 2018 jul 11
PublikationskategoriForskning
Peer review utfördJa