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Related papers: Carbon-enhanced metal-poor stars in the SDSS-APOGE…

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Carbon-enhanced metal-poor (CEMP) stars are a unique resource for Galactic archaeology because they probe the properties of the First Stars, early chemical evolution and binary interactions at very low metallicity. Comparing the fractions…

From high-resolution VLT/UVES spectra (R~43,000), we determine abundances or upper limits for Li, C, N, O, and other important elements, as well as 12C/13C isotopic ratio for three Carbon enhanced metal poor stars. All three stars have…

A substantial fraction of the lowest metallicity stars show very high enhancements in carbon. It is debated whether these enhancements reflect the stars' birth composition, or if their atmospheres were subsequently polluted, most likely by…

Solar and Stellar Astrophysics · Physics 2015-06-19 Else Starkenburg , Matthew D. Shetrone , Alan W. McConnachie , Kim A. Venn

A substantial fraction of metal-poor stars in the local Milky Way halo exhibit large overabundances of carbon. These stars, dubbed Carbon-Enhanced Metal-Poor (CEMP) stars, provide crucial constraints on the nature of the early universe…

Recent large-scale multi-band photometric surveys now enable elemental-abundance estimates for millions of stars with accuracies approaching those of low- to medium-resolution spectroscopy. Using [Fe/H] and [C/Fe] estimates derived from the…

\sdsszeroeight\ (V = 11.4; [Fe/H] = $-$3.1) and \sdssonethree\ (V = 12.4; [Fe/H] = $-$3.2) were observed with the SDSS 2.5-m telescope as part of the SDSS-MARVELS spectroscopic pre-survey, and were identified as extremely metal-poor (EMP;…

We present detailed chemical abundances for the bright carbon-enhanced metal-poor (CEMP) star BD+44 493, previously reported on by Ito et al. Our measurements confirm that BD+44 493 is an extremely metal-poor ([Fe/H]=-3.8) subgiant star…

Solar and Stellar Astrophysics · Physics 2015-06-16 H. Ito , W. Aoki , T. C. Beers , N. Tominaga , S. Honda

The fraction of binary systems in various stellar populations of the Galaxy and the distribution of their orbital parameters are important but not well-determined factors in studies of star formation, stellar evolution, and Galactic…

Solar and Stellar Astrophysics · Physics 2015-06-23 Wako Aoki , Takuma Suda , Timothy C. Beers , Satoshi Honda

We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High…

We have compiled composition, luminosity, and binarity information for carbon-enhanced, metal-poor (CEMP) stars reported by recent studies. We divided the CEMP star sample into two classes, having high and low abundances, respectively, of…

Astrophysics · Physics 2009-11-13 S. G. Ryan , W. Aoki , J. E. Norris , T. C. Beers

We discuss radial velocities for a sample of carbon-enhanced, s-process rich, very metal-poor stars (CEMP-s hereafter), analyzed with high-resolution spectroscopy obtained over multiple epochs. We find that ~68% of the stars in the sample…

We report estimated carbon-abundance ratios, [C/Fe], for seven newly-discovered carbon-enhanced metal-poor (CEMP) RR Lyrae stars. These are well-studied RRab stars that had previously been selected as CEMP candidates based on low-resolution…

We report on an abundance analysis for a pilot study of seven Carbon-Enhanced Metal-Poor (CEMP) stars, based on medium-resolution optical and near-infrared spectroscopy. The optical spectra are used to estimate [Fe/H], [C/Fe], [N/Fe], and…

It is known that the carbon-enhanced, extremely metal-poor (CEMP) stars constitute a substantial proportion in the extremely metal-poor (EMP) stars of the Galactic Halo, by far larger than CH stars in Population II stars. We investigate…

We have carried out a detailed abundance analysis for a sample of 16 carbon stars found among candidate extremely metal-poor (EMP) stars from the Hamburg/ESO Survey. We find that the Fe-metallicities for the cooler C-stars (Teff ~ 5100K)…

The origin of Carbon Enhanced Metal-Poor (CEMP-no) stars with low abundances of neutron-capture elements is still unclear. These stars are ubiquitous, found primarily in the Milky Way halo and ultra-faint dwarf galaxies (UFDs). To make a…

Astrophysics of Galaxies · Physics 2023-03-08 Martina Rossi , Stefania Salvadori , Ása Skúladóttir , Irene Vanni

We investigate the frequency and origin of carbon-enhanced metal-poor (CEMP) stars in Local Group dwarf galaxies by means of a statistical, data-calibrated cosmological model for the hierarchical build-up of the Milky Way and its dwarf…

Astrophysics of Galaxies · Physics 2015-10-14 Stefania Salvadori , Asa Skuladottir , Eline Tolstoy

Carbon-enhanced metal poor stars (CEMP) form a significant proportion of the metal-poor stars, their origin is not well understood. Three very metal-poor C-rich turnoff stars were selected from the SDSS survey, observed with the ESO VLT…

Astrophysics of Galaxies · Physics 2015-06-15 Monique Spite , E. Caffau , Piercarlo Bonifacio , François Spite , H. -G. Ludwig , Bertrand PLEZ , Norbert Christlieb

Metal-poor stars provide the fossil record of Galactic chemical evolution and the nucleosynthesis processes that took place at the earliest times in the history of our Galaxy. From detailed abundance studies of low mass, extremely…

Solar and Stellar Astrophysics · Physics 2015-03-11 T. Hansen , C. J. Hansen , N. Christlieb , D. Yong , T. C. Beers , J. Andersen

We present results from high-resolution (R $\sim 40,000$) spectroscopic observations of over 200 metal-poor stars, mostly selected from the RAVE survey, using the Southern African Large Telescope. We were able to derive stellar parameters…

Solar and Stellar Astrophysics · Physics 2022-03-14 Joseph Zepeda , Kaitlin C. Rasmussen , Timothy C. Beers , Vinicius M. Placco , Yang Huang , Éric Depagne