Chemical abundances in a metal-poor RGB star

DOI

We present chemical abundances for 27 elements ranging from oxygen to erbium in the metal-poor ([Fe/H]=-1.67) bulge red giant branch star 2MASS 18174532-3353235. The results are based on equivalent width and spectrum synthesis analyses of a high-resolution (R~30000) spectrum obtained with the Magellan-MIKE spectrograph. While the light (Z<~30) element abundance patterns match those of similar metallicity bulge and halo stars, the strongly enhanced heavy element abundances are more similar to "r-II" halo stars (e.g., CS 22892-052) typically found at [Fe/H]=56) closely follow the scaled-solar r-process abundance pattern. We do not find evidence supporting significant s-process contributions; however, the intermediate mass elements (e.g., Y and Zr) appear to have been produced through a different process than the heaviest elements. The light and heavy element abundance patterns of 2MASS 18174532-3353235 are in good agreement with the more metal-poor r-process enhanced stars CS 22892-052 and BD +17{deg}3248. 2MASS 18174532-3353235 also shares many chemical characteristics with the similar metallicity but comparatively {alpha}-poor Ursa Minor dwarf galaxy giant COS 82. Interestingly, the Mo and Ru abundances of 2MASS 18174532-3353235 are also strongly enhanced and follow a similar trend recently found to be common in moderately metal-poor main-sequence turn-off halo stars.

Identifier
DOI http://doi.org/10.26093/cds/vizier.17759027
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/775/L27
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/775/L27
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/775/L27
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/775/L27
Provenance
Creator Johnson C.I.; McWilliam A.; Rich R.M.
Publisher CDS
Publication Year 2015
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interdisciplinary Astronomy; Natural Sciences; Physics; Stellar Astronomy