Temperature and metallicity scale of cool giants Virtual Observatory Resource

Authors
  1. Ghosh S.
  2. Ojha D.K.
  3. Ninan J.P.
  4. Published by
    CDS
Abstract

We present here quantitative diagnostic tools for cool giants that employ low-resolution near-infrared spectroscopy in the K band for stellar population studies. In this study, a total of 260 cool giants (177 stars observed with X-shooter and 83 stars observed with NIFS) are used covering a wider metallicity range than in earlier works. We measure equivalent widths of some of the selected important K-band spectral features like NaI, FeI, and ^12^CO after degrading the spectral resolution (R~1200) to investigate the spectral behaviour with fundamental parameters (e.g. effective temperature and metallicity). We derive empirical relations to measure effective temperature using the ^12^CO first-overtone band at 2.29 and 2.32{mu}m and show a detailed quantitative metallicity dependence of these correlations. We find that the empirical relations based on solar-neighborhood stars can incorporate large uncertainty in evaluating T_eff_ for metal-poor or metal-rich stars. Furthermore, we explore all the spectral lines to establish the empirical relation with metallicity and find that the quadratic fit of the combination of NaI and ^12^CO at 2.29{mu}m lines yields a reliable empirical relation at [Fe/H]~<-0.4dex, while a linear fit of any line offers a good metallicity scale for stars having [Fe/H]>~0.0dex.

Keywords
  1. Giant stars
  2. Effective temperature
  3. Metallicity
  4. Line intensities
  5. Milky Way Galaxy
  6. Magellanic Clouds
  7. Infrared astronomy
  8. Spectroscopy
Bibliographic source Bibcode
2021MNRAS.501.4596G
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/501/4596
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/501/4596

Access

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http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/501/4596
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/501/4596
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/501/4596
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http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/501/4596/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/501/4596/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/501/4596/table1?

History

2023-11-15T09:21:37Z
Resource record created
2023-11-15T08:22:04Z
Updated
2023-11-15T09:21:37Z
Created

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