M-type stars in LAMOST DR5 unclassified spectra Virtual Observatory Resource

Authors
  1. Guo Y.-X.
  2. Luo A.-L.
  3. Zhang S.
  4. Du B.
  5. Wang Y.-F.
  6. Chen J.-J.
  7. Zuo F.,Kong X.
  8. Hou Y.-H.
  9. Published by
    CDS
Abstract

Our study aims to recognize M-type stars which are classified as 'UNKNOWN' due to poor quality in the Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) DR5 V1. A binary nonlinear hashing algorithm based on Multi-Layer Pseudo-Inverse Learning (ML-PIL) is proposed to effectively learn spectral features for M-type-star detection, which can overcome the bad fitting problem of template matching, particularly for low S/N spectra. The key steps and the performance of the search scheme are presented. A positive data set is obtained by clustering the existing M-type spectra to train the ML-PIL networks. By employing this new method, we find 11410 M-type spectra out of 642178 'UNKNOWN' spectra, and provide a supplemental catalogue. Both the supplemental objects and released M-type stars in DR5 V1 are composed of a whole M-type sample, which will be released in the official DR5 to the public in June 2019. All the M-type stars in the data set are classified as giants and dwarfs by two suggested separators: (1) a colour diagram of H versus J-K from 2MASS, (2) line indices CaOH versus CaH1, and the separation is validated with the Hertzsprung-Russell diagram (HRD) derived from Gaia DR2. The magnetic activities and kinematics of M dwarfs are also provided with the equivalent width (EW) of the H{alpha} emission line and the astrometric data from Gaia DR2 respectively.

Keywords
  1. spectroscopy
  2. m-stars
  3. late-type-stars
  4. visible-astronomy
Bibliographic source Bibcode
2019MNRAS.485.2167G
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/485/2167
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/485/2167
Document Object Identifer DOI
doi:10.26093/cds/vizier.74852167

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/485/2167
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/485/2167
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/485/2167
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http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/485/2167/catalog?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/485/2167/catalog?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/485/2167/catalog?

History

2022-11-17T14:36:00Z
Resource record created
2022-11-17T14:36:00Z
Created
2024-08-19T20:17:17Z
Updated

Contact

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