Estimation of the Gould Belt Scale Height from T Tauri Type Stars in the Gaia DR2 Catalog

Abstract

—We analyze the spatial and kinematic properties of a large sample of young T Tauri type stars in a 500 pc radius solar neighborhood, closely related to the Gould belt. The following parameters of the exponential density distribution have been determined: the average $${{({{z}_{{\text{G}}}})}_{ \odot }} = - 25 \pm 5$$ pc and scale height $${{h}_{{\text{G}}}} = 56 \pm 6$$ pc. We propose a method of excluding background stars from the samples, which are located at large heights with respect to the symmetry plane of the Gould belt. We discovered that the expansion effect for the entire star system, K_G = 6 ± 1 km s^‑1 kpc^‑1, is determined mainly by the dynamics of the Scorpius–Centaurus association. We show that the angular velocity of the residual intrinsic rotation of the Gould belt can reach Ω_G = 6.9 ± 0.2 km s^‑1 kpc^‑1 and that this rotation is opposite to the galactic rotation.