M-subdwarf research. II. Catalog of ~3000 subdwarfs Virtual Observatory Resource

Authors
  1. Zhang S.
  2. Luo A.-L.
  3. Comte G.
  4. Wang R.
  5. Li Y.-B.
  6. Du B.
  7. Hou W.
  8. Qin Li,Gizis J.
  9. Chen J.-J.
  10. Chen X.-L.
  11. Lu Y.
  12. Song Y.-H.
  13. Zhang H.-W.
  14. Zuo F.
  15. Published by
    CDS
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.

Keywords
  1. m-stars
  2. subdwarf-stars
  3. visible-astronomy
  4. spectroscopy
  5. proper-motions
  6. radial-velocity
  7. trigonometric-parallax
Bibliographic source Bibcode
2021ApJ...908..131Z
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/908/131
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/908/131
Document Object Identifer DOI
doi:10.26093/cds/vizier.19080131

Access

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http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/908/131
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https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/908/131/table4?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/908/131/table4?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/908/131/table4?

History

2024-02-29T08:32:26Z
Resource record created
2024-02-29T08:32:26Z
Created
2025-02-12T20:08:55Z
Updated

Contact

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CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr