Stellar parametrization of LAMOST M dwarf stars

Jiadong Li, Chao Liu, Bo Zhang, Hao Tian

M dwarf stars are the most common stars in the Galaxy, dominating the population of the Galaxy by numbers 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 be determined. In this paper, we present a catalog of the spectroscopic stellar parameters (Teff and [M/H]) of ∼ 300,000 M dwarf stars observed by both LAMOST and Gaia using Stellar Label Machine (SLAM). We train a SLAM model using LAMOST spectra with APOGEE Data Release 16 (DR16) labels with 2800<Teff<4500K and −2<[M/H]<0.5 dex. The SLAM Teff is in agreement to within ∼50K compared to the previous study determined by APOGEE observation, and SLAM [M/H] agree within 0.12 dex compared to the APOGEE observation. We also set up a SLAM model trained by BT-Settl atmospheric model, with random uncertainties (in cross-validation) to 60K and agree within ∼90K compared to previous study.

https://arxiv.org/abs/2012.14080