RAVE, SEGUE and Hipparcos data are used to study the dynamics of stars in the extended solar neighbourhood. The asymmetric drift of thin disc dwarfs is studied as a function of colour and metallicity. Linear extrapolation of the data falls within the error bars from Aumer & Binney (2009) for local standard of rest. The observed metallicity dependence of the asymmetric drift is consistent with the known radial metallicity distribution in the disc. Implying the asymmetric drift correction to the SEGUE data allows us to reconstruct the behaviour of the rotation curve of the Milky Way in the extended solar neighbourhood. The rotation curve appears to be eßentially flat, giving no hint for a dip just outside the solar radius followed by an increase observed in some other data sets. The data are supplemented by tangent point measurements for the inner rotation curve. Thus a synthetic rotation curve of the Milky Way is obtained. It is fitted by a density model consisting of a Dehnen bulge, an exponential disc with a hole, and a flattened dark matter halo with either cored isothermal or NFW density profile. In this fitting the parameters are constrained to reproduce the local surface density of the disc and the local volume density of the halo, which are known from local stellar dynamics in the solar neighbourhood. Thus the density model of the Milky Way is reconstructed. The vertical structure of the disc of theMilkyWay is consistent with the model by Just & Jahreiß (2010). Some basic features of distribution functions of the Milky Way and of the dynamical heating are also discussed.
|Supervisor:||Just, Prof. Dr. Andreas|
|Date of thesis defense:||9 November 2012|
|Date:||5 September 2012|
|Faculties / Institutes:||The Faculty of Physics and Astronomy > Dekanat der Fak. für Physik und Astronomie|
|Subjects:||520 Astronomy and allied sciences|