Chemical Properties of the Local Disk and Halo. II. Abundances of 3745 M Dwarfs and Subdwarfs from Improved Model Fitting of Low-resolution Spectra

Abstract We present a model-fit pipeline to determine the stellar parameters of M-type dwarfs, which is an improvement on our previous work described in Hejazi et al. apply this analyze low-resolution ( R ? 2000) spectra 3745 M dwarfs/subdwarfs, collected at MDM Observatory, Lick Kitt Peak National and Cerro Tololo Inter-American Observatory. examine variation inferred parameter values H-R diagram constructed from their Gaia Early Data Release 3 (EDR3) parallaxes optical magnitudes. also study distribution stars abundance [ ? /Fe] versus [M/H] inspect metallicity class, effective temperature, surface gravity, as well Galactic velocity components U , V W diagram. In addition, analyses stars’ projected motions two-dimensional UV VW UW planes, chemical these abundance?velocity diagrams are important parts study. The precision confirmed by clear stratification temperature diagram; similarity metallicity?velocity planes those other studies; revealing substructure diagrams; homogeneity between set binary systems.