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相关论文: Carbon-Enhanced Metal-Poor Stars in the Early Gala…

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We revisit the observed frequencies of Carbon-Enhanced Metal-Poor (CEMP) stars as a function of the metallicity in the Galaxy, using data from the literature with available high-resolution spectroscopy. Our analysis excludes stars…

太阳与恒星天体物理 · 物理学 2015-06-23 Vinicius M. Placco , Anna Frebel , Timothy C. Beers , Richard J. Stancliffe

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…

星系天体物理 · 物理学 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 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…

星系天体物理 · 物理学 2015-10-14 Stefania Salvadori , Asa Skuladottir , Eline Tolstoy

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…

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…

太阳与恒星天体物理 · 物理学 2025-09-23 Young Sun Lee , Timothy C. Beers , Yutaka Hirai , Jihye Hong , Miji Jeong , Changmin Kim , Young Kwang Kim

Carbon-enhanced metal-poor (CEMP) stars represent a sizeable fraction of all known metal-poor stars in the Galaxy. Their formation and composition remains a significant topic of investigation within the stellar astrophysics community. We…

太阳与恒星天体物理 · 物理学 2018-06-20 E. Caffau , A. J. Gallagher , P. Bonifacio , M. Spite , S. Duffau , F. Spite , L. Monaco , L. Sbordone

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…

The chemical compositions of 26 metal-poor stars that exhibit strong CH and/or C2 molecular bands are determined based on high-resolution spectroscopy. We define carbon-enhanced stars taking account of the carbon abundance ratio ([C/Fe])…

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…

太阳与恒星天体物理 · 物理学 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 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…

We report on early results from a pilot program searching for metal-poor stars with LAMOST and follow-up high-resolution observation acquired with the MIKE spectrograph attached to the Magellan~II telescope. We performed detailed abundance…

太阳与恒星天体物理 · 物理学 2015-01-14 Hai-Ning Li , Gang Zhao , Norbert Christlieb , Liang Wang , Wei Wang , Yong Zhang , Yonghui Hou , Hailong Yuan

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…

Approximately 20% of very metal-poor stars ([Fe/H] < -2.0) are strongly enhanced in carbon ([C/Fe] > +1.0). Such stars are referred to as carbon-enhanced metal-poor (CEMP) stars. We present a chemical abundance analysis based on high…

太阳与恒星天体物理 · 物理学 2015-05-14 N. T. Behara , P. Bonifacio , H. -G. Ludwig , L. Sbordone , J. I. Gonzalez Hernandez , E. Caffau

We report on oxygen abundances determined from medium-resolution near-IR spectroscopy for a sample of 57 carbon-enhanced metal-poor (CEMP) stars selected from the Hamburg/ESO survey. The majority of our program stars exhibit oxygen-to-iron…

The low-mass metal-poor stars in the Galaxy that preserve in their atmosphere, the chemical imprints of the gas clouds from which they were formed can be used as probes to get insight into the origin and evolution of elements in the early…

太阳与恒星天体物理 · 物理学 2023-11-17 Aruna Goswami , J Shejeelammal , Partha Pratim Goswami , Meenakshi Purandardas

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…

Metal-poor stars are a rare and ancient type of stars; Carbon-Enhanced Metal-Poor (CEMP) stars are a subset of these celestial bodies that show an enrichment of carbon relative to iron. They are believed to be formed from gas polluted by…

太阳与恒星天体物理 · 物理学 2025-05-09 Ziyu Fang , Xiangru Li , Haining Li

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…

太阳与恒星天体物理 · 物理学 2015-03-11 T. Hansen , C. J. Hansen , N. Christlieb , D. Yong , T. C. Beers , J. Andersen

The carbon-enhanced metal-poor (CEMP) stars constitute approximately one fifth of the metal-poor ([Fe/H] ~< -2) population but their origin is not well understood. The most widely accepted formation scenario, invokes mass-transfer of…

太阳与恒星天体物理 · 物理学 2015-05-14 Robert G. Izzard , Evert Glebbeek , Richard J. Stancliffe , Onno Pols
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