Metal-poor stars towards the Galactic bulge Virtual Observatory Resource

Authors
  1. Koch A.
  2. McWilliam A.
  3. Preston G.W.
  4. Thompson I.B.
  5. Published by
    CDS
Abstract

We present a comprehensive chemical abundance analysis of five red giants and two horizontal branch (HB) stars towards the south- ern edge of the Galactic bulge, at (l, b)~(0{deg}, -11{deg}). Based on high-resolution spectroscopy obtained with the Magellan/MIKE spectrograph, we derived up to 23 chemical element abundances and identify a mixed bag of stars, representing various populations in the central regions of the Galaxy. Although cosmological simulations predict that the inner Galaxy was host to the first stars in the Universe, we see no chemical evidence of the ensuing massive supernova explosions: all of our targets exhibit halo-like, solar [Sc/Fe] ratios, which is in contrast to the low values predicted from Population III nucleosynthesis. One of the targets is a CEMP-s star at [Fe/H]=-2.52dex, and another target is a moderately metal-poor ([Fe/H]=-1.53dex) CH star with strong enrichment in s-process elements (e.g., [Ba/Fe]=1.35). These individuals provide the first contenders of these classes of stars towards the bulge. Four of the carbon-normal stars exhibit abundance patterns reminiscent of halo star across a metallicity range spanning -2.0 to -2.6dex, i.e., enhanced {alpha}-elements and solar Fe-peak and neutron-capture elements, and the remaining one is a regular metal-rich bulge giant. The position, distance, and radial velocity of one of the metal-poor HB stars coincides with simulations of the old trailing arm of the disrupted Sagittarius dwarf galaxy. While their highly uncertain proper motions prohibit a clear kinematic separation, the stars' chemical abundances and distances suggest that these metal-poor candidates, albeit located towards the bulge, are not of the bulge, but rather inner halo stars on orbits that make them pass through the central regions. Thus, we caution similar claims of detections of metal-poor stars as true habitants of the bulge.

Keywords
  1. carbon-stars
  2. chemically-peculiar-stars
  3. population-ii-stars
  4. line-intensities
Bibliographic source Bibcode
2016A&A...587A.124K
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/587/A124
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/587/A124
Document Object Identifer DOI
doi:10.26093/cds/vizier.35870124

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/587/A124
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/587/A124
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/587/A124
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/A+A/587/A124/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/587/A124/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/587/A124/table1?

History

2016-03-02T08:11:57Z
Resource record created
2016-03-02T07:12:30Z
Updated
2016-03-02T08:11:57Z
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