Kinematics of the Galactic Disk Based on Open Cluster Data

Abstract

We study the dependence of the kinematic properties of the subsystems of Galactic open clusters on their ages. It was found that the angular velocity of Galactic rotation in the solar vicinity decreases to 25.6 km s\({}^{-1}\) kpc\({}^{-1}\) for clusters older than 600 Myrs. According to the rotation curves of the Galaxy for different age intervals at a galactocentric distance of 6.0 to 13.0 kpc, it is found that older open clusters rotate much more slowly than young and middle-aged clusters. The rotation curve decreases with increasing galactocentric distance in the entire distance interval under consideration. We can observe the separation of open clusters into thick and thin disk objects. A near-sinusoidal dependence of the radial cluster velocity component on galactocentric distance is obtained for distances ranging from 6.0 to 13.0 kpc. No dependence of the vertical velocity component on galactocentric distance is found.