Metal-poor stars from the HES using CH G-band

DOI

We describe a new method to search for metal-poor candidates from the Hamburg/ESO objective-prism survey (HES) based on identifying stars with apparently strong CH G-band strengths for their colors. The hypothesis we exploit is that large overabundances of carbon are common among metal-poor stars, as has been found by numerous studies over the past two decades. The selection was made by considering two line indices in the 4300{AA} region, applied directly to the low-resolution prism spectra. This work also extends a previously published method by adding bright sources to the sample. The spectra of these stars suffer from saturation effects, compromising the index calculations and leading to an undersampling of the brighter candidates. A simple numerical procedure, based on available photometry, was developed to correct the line indices and overcome this limitation. Visual inspection and classification of the spectra from the HES plates yielded a list of 5288 new metal-poor (and by selection, carbon-rich) candidates, which are presently being used as targets for medium-resolution spectroscopic follow-up. Estimates of the stellar atmospheric parameters, as well as carbon abundances, are now available for 117 of the first candidates, based on follow-up medium-resolution spectra obtained with the SOAR 4.1m and Gemini 8m telescopes. There are eight newly discovered stars with [Fe/H] < -3.0 in our sample, including two with [Fe/H] < -3.5.

Cone search capability for table J/AJ/142/188/table4 (Atmospheric parameters and carbonicity estimates for the observed candidates)

Cone search capability for table J/AJ/142/188/table5 (Candidate metal-poor stars)

Cone search capability for table J/AJ/142/188/table3 (Stellar data for the observed candidates)

Identifier
DOI http://doi.org/10.26093/cds/vizier.51420188
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/AJ/142/188
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/142/188
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/142/188
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/AJ/142/188
Provenance
Creator Placco V.M.; Kennedy C.R.; Beers T.C.; Christlieb N.; Rossi S.,Sivarani T.; Lee Y.S.; Reimers D.; Wisotzki L.
Publisher CDS
Publication Year 2013
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; Observational Astronomy; Physics; Stellar Astronomy