Kinematics of the Milky Way from the Gaia EDR3 red giants and subgiants

Abstract

ABSTRACT We present the results of the kinematic investigations carried out with the use of spatial velocities of red giants and subgiants contained in the Gaia EDR3 catalogue. The 12 kinematic parameters of the Ogorodnikov–Milne model have been derived for stellar systems with radii of 0.5 and 1.0 kpc, located along the direction of the Galactic Centre–the Sun–the Galactic anticentre within the range of Galactocentric distances R =  0–8–16 kpc. By combining some of the local parameters, the information related to the Galaxy as a whole has been received in the distance range of 4–12 kpc, in particular the circular velocity curve of red giant and subgiant centroids, its slope, and velocity gradients. We show that when using this approach, there is an alternative possibility to infer the behaviour of the circular velocity curve of red giant and subgiant centroids and its slope without using the Galactocentric distance R⊙. The kinematic parameters derived within the solar vicinity of 1 kpc radius are in good agreement with those given in the literature.