Related papers: The Most Metal-Poor Stars. III. The Metallicity Di…

We present and discuss the results of a search for extremely metal-poor stars based on photometry from data release DR1.1 of the SkyMapper imaging survey of the southern sky. In particular, we outline our photometric selection procedures…

We present the analysis of four new extremely metal poor turn-off stars thanks to high-resolution spectra obtained with the Subaru/HDS spectrograph. We determined the abundances and upper limits of Li, C, Mg, Ca, Sr, and Ba. Metallicities…

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)…

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…

Extremely metal-poor stars are intrinsically rare, but emerging methods exist to accurately classify them from all-sky Gaia XP low-resolution spectra. To assess their overall accuracy for targeting metal-poor stars, we present a…

Carbon-enhanced metal-poor (CEMP) stars are the living fossils holding records of chemical enrichment from early generations of stars. In this work, we perform a set of numerical simulations of the enrichment from a supernova (SN) of a…

Early phases of the chemical evolution and formation history of extremely metal poor (EMP) stars are investigated using hierarchical galaxy formation models. We build a merger tree of the Galaxy according to the extended Press-Schechter…

The chemical abundances of large samples of extremely metal-poor (EMP) stars can be used to investigate metal-free stellar populations, supernovae, and nucleosynthesis as well as the formation and galactic chemical evolution of the Milky…

We present the N, O, F and Na abundance and 12C/13C isotopic ratio measurements or upper limits for a sample of 10 C-rich, metal-poor giant stars, eight enhanced in s-process (CEMP-s) elements and two poor in n-capture elements (CEMP-no).…

We present a sample of 1777 bright (9<B<14) metal-poor candidates selected from the Hamburg/ESO Survey (HES). Despite saturation effects present in the red portion of the HES objective-prism spectra, the data were recoverable and…

We demonstrate that there are systematic scale errors in the [Fe/H] values determined by the Hamburg/ESO Survey (and by inference by the HK Survey in the past) for certain extremely metal poor highly C-enhanced giants. The consequences of…

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…

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…

We present uniformly measured stellar metallicities for 463 stars in 13 Milky Way (MW) ultra-faint dwarf galaxies (UFDs; $M_V = -7.1$ to $-0.8$) using narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST). This…

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 develop and test a method for the estimation of metallicities ([Fe/H]) and carbon abundance ratios ([C/Fe]) for carbon-enhanced metal-poor (CEMP) stars, based on application of artificial neural networks, regressions, and synthesis…

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…

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…

We exploit the recent observations of extremely metal-poor (EMP) stars in the Galactic halo and investigate the constraints on the IMF of the stellar population that left these low-mass survivors of [Fe/H]<-2.5 and the chemical evolution…

Mixing and fallback models in faint supernova models are supposed to reproduce the abundance patterns of observed carbon-enhanced metal-poor (CEMP) stars in the Galactic halo. A fine tuning of the model parameters for individual stars is…