Stellar Parameterization of LAMOST M Dwarf Stars

Abstract

The M dwarf stars are the most common stars in the Galaxy, dominating the population of the Galaxy at faint magnitudes. Precise and accurate stellar parameters for M dwarfs are of crucial importance for many studies. However, the atmospheric parameters of M dwarf stars are difficult to determine. In this paper, we present a catalog of the spectroscopic stellar parameters (T_eff and [M/H]) of ∼300,000 M dwarf stars observed by both LAMOST and Gaia using the Stellar LAbel Machine (SLAM). We train a SLAM model using LAMOST spectra with APOGEE Data Release 16 labels with 2800 K < T_eff < 4500K and -2 dex < [M/H] < 0.5 dex. The SLAM T_eff is in agreement to within ∼50 K compared to the previous study determined by APOGEE observations, and the SLAM [M/H] agrees within 0.12 dex compared to the APOGEE observation. We also set up a SLAM model trained by the BT-Settl atmospheric model with random uncertainties (in cross validation) to 60 K and agreeing within ∼90 K compared to previous studies.