Estimation of stellar parameters and mass accretion rate of classical T Tauri stars from LAMOST DR6

Abstract

Classical T Tauri stars (TTS) are low-mass pre-main sequence stars with an active circumstellar environment. In this work, we present the identification and study of 260 classical TTS using LAMOST Data Release 6, among which 104 stars are newly identified. We distinguish classical TTS from giants and main-sequence dwarfs based on the \(\log {g}\) values, and the presence of H\(\alpha \) emission line and infrared excess that arises from the circumstellar accretion disk. We estimated the mass and age of 210 stars using the Gaia color–magnitude diagram. The age is from 0.1 to 20 Myr, where 90% of the stars have age <10 Myr and the mass ranges between 0.11 and 1.9 \(M_{\odot }\). From the measured H\(\alpha \) equivalent widths, we homogeneously estimated the mass accretion rates for 172 stars, with most values ranging from \(10^{-7}\) to \(10^{-10}\) \(M_{\odot }\) yr\(^{-1}\). The mass accretion rates are found to follow a power law distribution with the mass of the star, having a relation of the form \(\dot{M}_\textrm{acc}\propto M_{*} ^ {1.43 \pm 0.26}\), in agreement with previous studies.