相关论文: Carbon-Enhanced Metal-Poor Stars. III. Main-Sequen…

Chemical compositions are determined based on high-resolution spectroscopy for 137 candidate extremely metal-poor (EMP) stars selected from the Sloan Digital Sky Survey (SDSS) and its first stellar extension, the Sloan Extension for…

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…

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…

We present a comparison of the frequencies of carbon-enhanced metal-poor (CEMP) giant and main-sequence turnoff stars, selected from the Sloan Digital Sky Survey and the Sloan Extension for Galactic Understanding and Exploration, with…

By considering the various CEMP subclasses separately, we try to derive, from the specific signatures imprinted on the abundances, parameters (such as metallicity, mass, temperature, and neutron source) characterizing AGB nucleosynthesis…

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…

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…

We identify six new CEMP stars ([C/Fe]>+0.7 and [Fe/H]< -1.8) and another seven likely candidates within the APOGEE database following Data Release 12. These stars have chemical compositions typical of metal-poor halo stars, e.g., mean…

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])…

We describe a method for the determination of stellar [C/Fe] abundance ratios using low-resolution (R = 2000) stellar spectra from the SDSS and SEGUE. By means of a star-by-star comparison with a set of SDSS/SEGUE spectra with available…

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…

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)…

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…

We present a detailed study of Carbon-Enhanced Metal-Poor (CEMP) stars, based on high-resolution spectroscopic observations of a sample of 18 stars. The stellar spectra for this sample were obtained at the 4.2m William Herschel Telescope…

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 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…

Among Carbon-Enhanced Metal-Poor (CEMP) stars, some are found to be enriched in s-process elements (CEMP-s), in r-process elements (CEMP-r) or in both s- and r-process elements (CEMP-rs). The origin of the abundance differences between…

Many observed CEMP stars are found in binary systems and show enhanced abundances of $s$-elements. The origin of the chemical abundances of these CEMP-$s$ stars is believed to be accretion in the past of enriched material from a primary…

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…

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…