Accreted halo stars abundances Virtual Observatory Resource

Authors
  1. Carrillo A.
  2. Hawkins K.
  3. Jofre P.
  4. de Brito Silva D.
  5. Das P.
  6. Lucey M.
  7. Published by
    CDS
Abstract

Understanding the assembly of our Galaxy requires us to also characterize the systems that helped build it. In this work, we accomplish this by exploring the chemistry of accreted halo stars from the Gaia-Enceladus/Gaia-Sausage (GES) selected in the infrared from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) Data Release 16. We use high resolution optical spectra for 62 GES stars to measure abundances in 20 elements spanning the {alpha}, Fe-peak, light, odd-Z, and notably, the neutron-capture groups of elements to understand their trends in the context of and in contrast to the Milky Way and other stellar populations. Using these derived abundances we find that the optical and the infrared abundances agree to within 0.15 dex except for O, Co, Na, Cu, and Ce. These stars have enhanced neutron- capture abundance trends compared to the Milky Way, and their [Eu/Mg] and neutron-capture abundance ratios (e.g., [Y/Eu], [Ba/Eu], [Zr/Ba], [La/Ba], and [Nd/Ba]) point to r-process enhancement and a delay in s-process enrichment. Their [{alpha}/Fe] trend is lower than the Milky Way trend for [Fe/H]>-1.5dex, similar to previous studies of GES stars and consistent with the picture that these stars formed in a system with a lower rate of star formation. This is further supported by their depleted abundances in Ni, Na, and Cu abundances, again, similar to previous studies of low-{alpha} stars with accreted origins.

Keywords
  1. Milky Way Galaxy
  2. Halo stars
  3. Chemical abundances
  4. Optical astronomy
Bibliographic source Bibcode
2022MNRAS.513.1557C
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/513/1557
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/513/1557

Access

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http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/513/1557
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/513/1557
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/513/1557
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https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/513/1557/main?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/513/1557/main?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/513/1557/targets?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/513/1557/targets?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/513/1557/targets?

History

2022-05-31T07:05:31Z
Resource record created
2022-05-31T07:05:31Z
Created
2022-11-13T17:06:50Z
Updated

Contact

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CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr