Spectral indices of Galactic halo Virtual Observatory Resource

Authors
  1. Morrison H.L.
  2. Norris J.
  3. Mateo M.
  4. Harding P.
  5. Olszewski E.W.,Shectman S.A.
  6. Dohm-Palmer R.C.
  7. Helmi A.
  8. Freeman K.C.
  9. Published by
    CDS
Abstract

We present our calibration of spectroscopic measures of luminosity and metallicity for halo giant candidates and give metallicities and distances for our first sample of spectroscopically confirmed giants. These giants have distances ranging from 15 to 83kpc. As surveys reach farther into the Galaxy's halo with K giant samples, identification of giants becomes more difficult. This is because the numbers of foreground halo K dwarfs rise for V magnitudes of 19-20, typical for halo giants at 100kpc. Our photometric survey uses the strength of the Mgb/H feature near 5170{AA} to weed K dwarfs out of the disk and thick disk, but we need spectroscopic measures of the strength of the Ca II K, Ca I {lambda}4227, and Mgb/H features to distinguish between the very metal-poor dwarfs and halo giants. Using a full error analysis of our spectroscopic measures, we show why a signal-to-noise ratio of ~15pixel^-1^ at Ca I {lambda}4227 and ~10 at Ca II K is needed for reliable luminosity discrimination. We use the Ca II K and Mgb features to measure metallicity in our halo giants, with typical errors (random plus systematic) of 0.3dex for [Fe/H] values from -0.8 to -3.0.

Keywords
  1. halo-stars
  2. spectroscopy
  3. apparent-magnitude
  4. metallicity
Bibliographic source Bibcode
2003AJ....125.2502M
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/125/2502
IVOA Identifier IVOID
ivo://CDS.VizieR/J/AJ/125/2502
Document Object Identifer DOI
doi:10.26093/cds/vizier.51252502

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/125/2502
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/125/2502
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/125/2502
IVOA Table Access TAP
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).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/125/2502/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/125/2502/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/125/2502/table1?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/125/2502/table2?
https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/125/2502/table2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/125/2502/table2?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/125/2502/table6?
https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/125/2502/table6?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/125/2502/table6?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/125/2502/table7?
https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/125/2502/table7?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/125/2502/table7?

History

2003-12-29T16:21:34Z
Resource record created
2003-12-29T16:21:34Z
Created
2023-04-06T16:50:55Z
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