Thin disk kinematics from RAVE and the solar motion

¹ University College LondonDepartment of Space & Climate Physics, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking Surrey RH5 6NT, UK
e-mail: sp2@mssl.ucl.ac.uk
² Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, 69120 Heidelberg, Germany
³ University of Ljubljana, Faculty of Mathematics and Physics, 1000 Ljubljana, Slovenia
⁴ Center of Excellence SPACE-SI, Aškerčeva cesta 12, 1000 Ljubljana, Slovenia
⁵ Department of Physics and Astronomy “G. Galilei”, Padova University, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
⁶ INAF – Padova Astronomical Observatory, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
⁷ Observatoire astronomique de Strasbourg 11 rue de l’Université, 67000 Strasbourg, France
⁸ Sydney Institute for Astronomy, University of Sydney, 2006 NSW, Australia
⁹ Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE, UK
¹⁰ Monash Centre for Astrophysics, Monash University, 3800 Clayton, Australia
¹¹ Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA, UK
¹² University of Victoria, Department of Physics and Astronomy, Victoria, BC V8P 5C2, Canada
¹³ Department of Physics and Astronomy, Macquarie University, 2109 NSW, Australia
¹⁴ Macquarie research centre in Astronomy, Astrophysics and Astrophotonics, Macquarie University, 2109 NSW, Australia
¹⁵ Australian Astronomical Observatory, PO Box 296, Epping, 2121 NSW, Australia
¹⁶ Leibniz-Institut fur Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany

Received: 23 April 2012
Accepted: 24 August 2012

Abstract

Aims. We study the Milky Way (MW) thin disk with the RAdial Velocity Experiment (RAVE) survey. We consider the thin and thick disks as different Galactic components and present a technique to statistically disentangle the two populations. Then we focus our attention on the thin disk component.

Methods. We disentangle the thin disk component from a mixture of the thin and thick disks using a data set providing radial velocities, proper motions, and photometrically determined distances.

Results. We present the trend of the velocity dispersions in the thin disk component of the MW in the radial direction above and below the Galactic plane using data from the RAVE. The selected sample is a limited subsample from the entire RAVE catalogue, roughly mapping up to 500 pc above and below the Galactic plane, a few degrees in azimuthal direction and covering a radial extension of 2.0 kpc around the solar position. The solar motion relative to the local standard of rest is also re-determined with the isolated thin disk component. Major results are the trend of the velocity mean and dispersion in the radial and vertical direction. In addition the azimuthal components of the solar motion relative to the local standard of rest and the velocity dispersion are discussed.