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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 span a wide range of stellar populations, from bona fide second-generation stars to later forming stars that provide excellent probes of, e.g., binary mass transfer. Here we analyse 11 metal-poor…

In this work, we study the chemical compositions and kinematic properties of six metal-poor stars with [Fe/H] $< -2.5$ in the Galactic halo. From high-resolution (R $\sim$~110,000) spectroscopic observations obtained with the Lick/APF, we…

Astrophysics of Galaxies · Physics 2019-09-04 Mohammad K. Mardini , Vinicius M. Placco , Ali Taani , Haining Li , Gang Zhao

We report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in the metallicity range of $-3.3<$ [Fe/H] $<-2.4$. These stars were selected from the LAMOST DR3 low-resolution (R$ \sim$ 2,000) spectroscopic database as…

We estimate the frequency of Carbon-Enhanced Metal-Poor (CEMP) stars among very metal-poor stars, based on an analysis of 349 stars with available high-resolution spectra observed as part of the Hamburg/ESO R-process Enhanced Star (HERES)…

(Abridged) Carbon-enhanced metal-poor (CEMP) stars in the halo components of the Milky Way are explored, based on accurate determinations of the carbon-to-iron ([C/Fe]) abundance ratios and kinematic quantities for over 30000 calibration…

Astrophysics of Galaxies · Physics 2015-05-27 D. Carollo , T. C. Beers , J. Bovy , T. Sivarani , J. E. Norris , K. C. Freeman , W. Aoki , Y. S. Lee , C. R. Kennedy

We report the discovery of a new subclass of carbon-enhanced metal-poor (CEMP) stars, characterized by high absolute carbon abundances (A(C) > 7.39) and extremely low metallicity ([Fe/H] $<=$ -3.1) but notably lacking enhancements in…

Solar and Stellar Astrophysics · Physics 2025-09-23 Young Sun Lee , Timothy C. Beers , Yutaka Hirai , Jihye Hong , Miji Jeong , Changmin Kim , Young Kwang Kim

We present the results of an analysis for 107 extremely metal-poor (EMP) stars with metallicities less than [Fe/H] = -3.0, identified from medium-resolution spectra in SDSS. We follow a methodology based on comparisons of the observed…

Solar and Stellar Astrophysics · Physics 2016-09-07 E. Fernandez-Alvar , C. Allende Prieto , T. C. Beers , Y. S. Lee , T. Masseron , D. P. Schneider

Carbon enhanced metal poor (CEMP) stars are a particular class of low metalicity halo stars whose chemical analysis may provide important constrains to the chemistry evolution of the Galaxy and to the models of mass transfer and evolution…

Solar and Stellar Astrophysics · Physics 2017-09-20 M. Roriz , C. B. Pereira , N. A. Drake , F. Roig , J. V. Sales Silva

Carbon-enhanced metal-poor (CEMP) stars comprise a large percentage of stars at the lowest metallicities. The stars in the CEMP-no subcategory do not show any s-process enhancement and therefore cannot easily be explained by transfer of…

Solar and Stellar Astrophysics · Physics 2019-01-30 Anke Arentsen , Else Starkenburg , Matthew D. Shetrone , Kim A. Venn , Éric Depagne , Alan W. McConnachie

We have developed a new procedure to search for carbon-enhanced metal-poor (CEMP) stars from the Hamburg/ESO (HES) prism-survey plates. This method employs an extended line index for the CH G-band, which we demonstrate to have superior…

Detailed spectroscopic studies of metal-poor halo stars have highlighted the important role of carbon-enhanced metal-poor (CEMP) stars in understanding the early production and ejection of carbon in the Galaxy and in identifying the…

Solar and Stellar Astrophysics · Physics 2016-03-23 T. T. Hansen , J. Andersen , B. Nordström , T. C. Beers , V. M. Placco , J. Yoon , L. A. Buchhave

We report on a programme to monitor the radial velocities of a sample of candidate and confirmed carbon-enhanced, metal-poor (CEMP) stars. We observed 45 targets using the Echelle Spectrographs of three 4m class telescopes. Radial…

Astrophysics · Physics 2007-05-23 S. Tsangarides , S. G. Ryan , T. C. Beers

Carbon-enhanced metal-poor (CEMP) stars comprise almost a third of stars with [Fe/H] < --2, although their origins are still poorly understood. It is highly likely that one sub-class (CEMP-$s$ stars) is tied to mass-transfer events in…

We explore the kinematics and orbital properties of a sample of 323 very metal-poor stars in the halo system of the Milky Way, selected from the high-resolution spectroscopic follow-up studies of Aoki et al. and Yong et al. The combined…

Astrophysics of Galaxies · Physics 2015-06-18 Daniela Carollo , Ken Freeman , Timothy Beers , Vinicius Placco , Jason Tumlinson , Sarah Martell

The chemical compositions of seven Carbon-Enhanced Metal-Poor (CEMP) turn-off stars are determined from high-resolution spectroscopy. Five of them are selected from the SDSS/SEGUE sample of metal-poor stars. The effective temperatures of…

We report on the discovery of seven low-metallicity stars selected from the Hamburg/ESO Survey, six of which are extremely metal-poor ([Fe/H]<-3.0), with four having [Fe/H]<-3.5. Chemical abundances or upper limits are derived for these…

In the course of the TOPoS (Turn Off Primordial Stars) survey, aimed at discovering the lowest metallicity stars, we have found several carbon-enhanced metal-poor (CEMP) stars. We here present our analysis of six CEMP stars. Calcium and…

An increasing fraction of carbon-enhanced metal-poor (CEMP) stars is found as their iron abundance, [Fe/H], decreases below [Fe/H] = -2.0. The CEMP-s stars have the highest absolute carbon abundances, [C/H], and are thought to owe their…

Solar and Stellar Astrophysics · Physics 2016-03-21 C. J. Hansen , B. Nordstroem , T. T. Hansen , C. R. Kennedy , V. M. Placco , T. C. Beers , J. Andersen , G. Cescutti , C. Chiappini

Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M > 0.8 Msun) that are now extinct. In particular, it is expected that the observed abundance of Li should deviate in these stars from…

Solar and Stellar Astrophysics · Physics 2012-06-01 T. Masseron , J. A. Johnson , S. Lucatello , A. Karakas , B. Plez , T. C. Beers , N. Christlieb

Very metal-deficient stars that exhibit enhancements of their carbon abundances are of crucial importance for understanding a number of issues -- the nature of stellar evolution among the first generations of stars, the shape of the Initial…

Astrophysics · Physics 2009-11-10 B. Marsteller , T. C. Beers , S. Rossi , N. Christlieb , M. Bessell , J. Rhee
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