Galaxy halo Extremely Metal-Poor stars Virtual Observatory Resource

Authors
  1. Cordoni G.
  2. Da Costa G.S.
  3. Yong D.
  4. Mackey A.D.
  5. Marino A.F.
  6. Monty S.,Nordlander T.
  7. Norris J.E.
  8. Asplund M.
  9. Bessell M.S.
  10. Casey A.R.,Frebel A.
  11. Lind K.
  12. Murphy S.J.
  13. Schmidt B.P.
  14. Gao X.D.,Xylakis-Dornbusch T.
  15. Amarsi A.M.
  16. Milone A.P.
  17. Published by
    CDS
Abstract

In this work, we combine spectroscopic information from the SkyMapper survey for Extremely Metal-Poor stars and astrometry from Gaia DR2 to investigate the kinematics of a sample of 475 stars with a metallicity range of -6.5<=[Fe/H]<=-2.05dex. Exploiting the action map, we identify 16 and 40 stars dynamically consistent with the Gaia Sausage and Gaia Sequoia accretion events, respectively. The most metal poor of these candidates have metallicities of [Fe/H]=-3.31 and -3.74, respectively, helping to define the low-metallicity tail of the progenitors involved in the accretion events. We also find, consistent with other studies, that ~21 per cent of the sample have orbits that remain confined to within 3kpc of the Galactic plane, that is, |Z_max_|<=3kpc. Of particular interest is a subsample (~11 per cent of the total) of low |Z_max_| stars with low eccentricities and prograde motions. The lowest metallicity of these stars has [Fe/H]=-4.30 and the subsample is best interpreted as the very low-metallicity tail of the metal-weak thick disc population. The low |Z_max_|, low eccentricity stars with retrograde orbits are likely accreted, while the low |Z_max_|, high eccentricity pro- and retrograde stars are plausibly associated with the Gaia Sausage system. We find that a small fraction of our sample (~4 per cent of the total) is likely escaping from the Galaxy, and postulate that these stars have gained energy from gravitational interactions that occur when infalling dwarf galaxies are tidally disrupted.

Keywords
  1. Milky Way Galaxy
  2. Chemically peculiar stars
  3. Stellar distance
Bibliographic source Bibcode
2021MNRAS.503.2539C
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/503/2539
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/503/2539

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/503/2539
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/503/2539
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/503/2539
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).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/503/2539/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/503/2539/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/503/2539/table1?

History

2024-03-04T15:50:00Z
Resource record created
2024-03-04T14:51:25Z
Updated
2024-03-04T15:50:00Z
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