Galactic Rotation Parameters Based on Stars from Active Star-Forming Regions with Data from the Gaia DR2 Catalogue

Abstract

We have studied a sample of more than 25 000 young stars with proper motions and trigonometric parallaxes from the Gaia DR2 catalogue. The relative errors of their parallaxes do not exceed 10$%$. The selection of stars belonging to active star-forming regions was made by Marton et al. based on data from the Gaia DR2 catalogue by invoking infrared measurements from the WISE and Planck catalogues. Low-mass T Tauri stars constitute the majority of sample stars. The following parameters of the angular velocity of Galactic rotation have been found from them: $Ω₀=28.40± 0.11$ km s${}^{-1}$ kpc${}^{-1}$, $Ω^'₀=-3.933± 0.033$ km s${}^{-1}$ kpc${}^{-2}$, and $Ω^''₀=0.804± 0.040$ km s${}^{-1}$ kpc${}^{-3}$. The Oort constants are $A=15.73± 0.32$ km s${}^{-1}$ kpc${}^{-1}$ and $B=-12.67± 0.34$ km s${}^{-1}$ kpc${}^{-1}$, while the circular rotation velocity of the solar neighborhood around the Galactic center is $V₀=227± 4$ km s${}^{-1}$ for the adopted Galactocentric distance of the Sun $R₀=8.0± 0.15$ kpc.