Carbon-enhanced metal-poor (CEMP) star abundances Virtual Observatory Resource

Authors
  1. Yoon J.
  2. Beers T.C.
  3. Placco V.M.
  4. Rasmussen K.C.
  5. Carollo D.
  6. He S.,Hansen T.T.
  7. Roederer I.U.
  8. Zeanah J.
  9. Published by
    CDS
Abstract

We investigate anew the distribution of absolute carbon abundance, A(C)=log{epsilon}(C), for carbon-enhanced metal-poor (CEMP) stars in the halo of the Milky Way, based on high-resolution spectroscopic data for a total sample of 305 CEMP stars. The sample includes 147 CEMP-s (and CEMP-r/s) stars, 127 CEMP-no stars, and 31 CEMP stars that are unclassified, based on the currently employed [Ba/Fe] criterion. We confirm previous claims that the distribution of A(C) for CEMP stars is (at least) bimodal, with newly determined peaks centered on A(C)=7.96 (the high-C region) and A(C)=6.28 (the low-C region). A very high fraction of CEMP-s (and CEMP-r/s) stars belongs to the high-C region, while the great majority of CEMP-no stars resides in the low-C region. However, there exists complexity in the morphology of the A(C)-[Fe/H] space for the CEMP-no stars, a first indication that more than one class of first-generation stellar progenitors may be required to account for their observed abundances. The two groups of CEMP-no stars we identify exhibit clearly different locations in the A(Na)-A(C) and A(Mg)-A(C) spaces, also suggesting multiple progenitors. The clear distinction in A(C) between the CEMP-s (and CEMP-r/s) stars and the CEMP-no stars appears to be as successful, and likely more astrophysically fundamental, for the separation of these sub-classes as the previously recommended criterion based on [Ba/Fe] (and [Ba/Eu]) abundance ratios. This result opens the window for its application to present and future large-scale low- and medium-resolution spectroscopic surveys.

Keywords
  1. chemical-abundances
  2. chemically-peculiar-stars
  3. carbon-stars
Bibliographic source Bibcode
2016ApJ...833...20Y
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/833/20
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/833/20
Document Object Identifer DOI
doi:10.26093/cds/vizier.18330020

Access

Web browser access HTML
https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/833/20
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/833/20
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/833/20
IVOA Table Access TAP
https://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/ApJ/833/20/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/833/20/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/833/20/table1?

History

2017-04-19T08:31:22Z
Resource record created
2017-04-19T08:31:22Z
Created
2018-07-04T07:17:12Z
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