J/ApJ/908/131 M-subdwarf research. II. Catalog of ~3000 subdwarfs (Zhang+, 2021) ================================================================================ M-subdwarf research. II. Atmospheric parameters and kinematics. Zhang S., Luo A.-L., Comte G., Wang R., Li Y.-B., Du B., Hou W., Qin Li, Gizis J., Chen J.-J., Chen X.-L., Lu Y., Song Y.-H., Zhang H.-W., Zuo F. =2021ApJ...908..131Z ================================================================================ ADC_Keywords: Stars, M-type; Stars, subdwarf; Spectra, optical; Proper motions; Radial velocities; Parallaxes, trigonometric Keywords: M subdwarf stars Abstract: We applied the revised M subdwarf classification criteria discussed in Zhang+ 2019, J/ApJS/240/31 (Paper I) to Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR7 and combined the result with the M subdwarf sample from Savcheva+ 2014ApJ...794..145S to construct a new M subdwarf sample for further study. The atmospheric parameters for each object were derived from fitting to the PHOENIX grid, and the sources with available astrometry and photometry from Gaia DR2 were combined for further analysis. The relationship between the gravity and metallicity was explored according to the locus both in the color-absolute magnitude diagram and the reduced proper motion diagram. Objects that have both the largest gravity and the lowest metallicity are located away from the main-sequence cloud and may be considered as the intrinsic M subdwarfs, which can be classified as luminosity class VI. Another group of objects whose spectra show typical M subdwarf characteristics have lower gravity and relatively moderate metal deficiency and occupy part of the ordinary M dwarf region in both diagrams. The Galactic U, V, W space velocity components and their dispersion show that the local Galactic halo population sampled in the solar neighborhood is represented by objects of high gravity and an inconspicuous bimodal metallicity distribution, with a fraction of prograde orbits. The other M subdwarfs seem to belong in part to the thick disk component, with a significant fraction of thin disk, moderately metal-poor objects intricately mixed with them. However, selection effects, especially the favored anticenter direction of investigation in the LAMOST subsample, as well as contamination by multiplicity and parameter coupling, could play important roles and need to be investigated further. Description: The low-resolution spectra of M dwarfs and subdwarfs are from LAMOST DR7 and SDSS DR7, and the astrometric data is from Gaia DR2. LAMOST is a reflecting Schmidt telescope located at the Xinglong Station of the National Astronomical Observatory, China, with a mean aperture of 4.3m and a field of view of 5deg. A total of 4000 optical fibers positioned on the focal plane yield a high spectrum acquisition rate per night. Until 2020 March, DR7 published more than 10 million low-resolution spectra (R~1800) covering 3800-9000{AA} and 2.17 million medium resolution spectra (R~7500) covering 3700-5900{AA} and 5700-9000{AA}. SDSS DR7 was collected by a dedicated wide-field 2.5m telescope at Apache Point Observatory. The telescope employed a drift-scan technique, imaging the sky in u, g, r, i, and z wide bands along five camera columns. The fiber-fed spectrographs acquired 640 spectra (R~2000) simultaneously, and the spectral range is 3800-9200{AA}. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table4.dat 863 3131 Subdwarf catalog -------------------------------------------------------------------------------- See also: VII/195 : Globular Clusters in the Milky Way (Harris, 1996) VII/202 : Globular Clusters in the Milky Way (Harris, 1997) III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997) II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009) I/345 : Gaia DR2 (Gaia Collaboration, 2018) I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018) V/156 : LAMOST DR7 catalogs (Luo+, 2019) V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020) I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022) J/AJ/113/806 : M-Subdwarfs (Gizis 1997) J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003) J/AJ/125/1598 : High proper motion stars in northern sky (Lepine+, 2003) J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003) J/PASP/115/22 : Stellar parameters for 134 cool subdwarfs (Yong+, 2003) J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004) J/AJ/130/1658 : High proper motion stars (-47