The role of binaries in the enrichment of the early Galactic halo. II. Carbon-Enhanced Metal-Poor Stars - CEMP-no stars

  title={The role of binaries in the enrichment of the early Galactic halo. II. Carbon-Enhanced Metal-Poor Stars - CEMP-no stars},
  author={Terese T. Hansen and Johannes Andersen and Birgitta Nordstrom and Timothy C. Beers and Vinicius M. Placco and J. Yoon and Lars A. Buchhave},
  journal={arXiv: Solar and Stellar Astrophysics},
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 progenitors of the CEMP stars among the first stars formed after the Big Bang. Recent work has also classified the CEMP stars by absolute carbon abundance, A(C), into high- and low-C bands, mostly populated by binary and single stars, respectively. Our aim is to… Expand
Are Faint Supernovae Responsible for Carbon-enhanced Metal-poor Stars?
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 theExpand
Oxygen abundances of carbon-enhanced stellar population in the halo
The large fraction of carbon-enhanced metal-poor (CEMP) stars at lower metallicities makes them an interesting class of objects to be probed further in greater detail. They show different abundanceExpand
Abundances and kinematics of carbon-enhanced metal-poor stars in the Galactic halo
  • C. J. Hansen, T. Hansen, +4 authors J. Andersen
  • Physics
  • Astronomy & Astrophysics
  • 2019
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 binary mass transferExpand
Abundance analysis of a CEMP-no star in the Carina dwarf spheroidal galaxy
Carbon-enhanced metal-poor (CEMP) stars bear important imprints of the early chemical enrichment of any stellar system. While these stars are known to exist in copious amounts in the Milky Way halo,Expand
Abundances of carbon-enhanced metal-poor stars as constraints on their formation
Context. 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 carbonExpand
Radiative levitation in carbon-enhanced metal-poor stars with s-process enrichment
A significant fraction of all metal-poor stars are carbon-rich. Most of these carbon-enhanced metal-poor (CEMP) stars also show enhancement in elements produced mainly by the s-process (CEMP-s stars)Expand
Binarity among CEMP-no stars: an indication of multiple formation pathways?
Carbon-enhanced metal-poor (CEMP) stars comprise a high percentage of stars at the lowest metallicities. The stars in the CEMP-no subcategory do not show any s-process enhancement and thereforeExpand
The role of faint population III supernovae in forming CEMP stars in ultra-faint dwarf galaxies
CEMP-no stars, a subset of carbon enhanced metal poor (CEMP) stars ([C/Fe] ≥ 0.7 and [Fe/H] . −1) have been discovered in ultra-faint dwarf (UFD) galaxies, with Mvir ≈ 108 M and M∗ ≈ 103 − 104 M at zExpand
On Neutron Star Mergers as the Source of r-process-enhanced Metal-poor Stars in the Milky Way
We model the history of Galactic r-process enrichment using high-redshift, high-resolution zoom cosmological simulations of a Milky Way (MW) type halo. We assume that all r-process sources areExpand
Identification of a Group III CEMP-no Star in the Dwarf Spheroidal Galaxy Canes Venatici I
CEMP-no stars, a subclass of carbon-enhanced metal-poor (CEMP) stars, are one of the most significant stellar populations in Galactic Archaeology, because they dominate the low end of the metallicityExpand


The role of binaries in the enrichment of the early Galactic halo I. r-process-enhanced metal-poor stars
Context. The detailed chemical composition of most metal-poor halo stars has been found to be highly uniform, but a minority of stars exhibit dramatic enhancements in their abundances of heavyExpand
Modelling the observed properties of carbon-enhanced metal-poor stars using binary population synthesis
The stellar population in the Galactic halo is characterised by a large fraction of carbon-enhanced metal-poor (CEMP) stars. Most CEMP stars have enhanced abundances of s-process elements (CEMP-sExpand
Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution - I. Detailed analysis of 15 binary stars with known orbital periods
AGB stars are responsible for producing a variety of elements, including carbon, nitrogen, and the heavy elements produced in the slow neutron-capture process (s-elements). There are manyExpand
Wind Roche-lobe overflow: Application to carbon-enhanced metal-poor stars
Carbon-enhanced metal-poor stars (CEMP) are observed as a substantial fraction of the very metal-poor stars in the Galactic halo. Most CEMP stars are also enriched in s-process elements and these areExpand
Binarity in carbon-enhanced metal-poor stars
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 atmospheresExpand
Carbon-enhanced metal-poor stars in the inner and outer halo components of the Milky Way
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 quantitiesExpand
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 ofExpand
Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M {approx}> 0.8 M{sub Sun }) that are now extinct. In particular, it is expected that theExpand
First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
In the framework of the ESO Large Programme "First Stars", very high-quality spectra of some 70 very metal-poor dwarfs and giants were obtained with the ESO VLT and UVES spectrograph. These stars areExpand
Binary properties of CH and Carbon-Enhanced Metal-Poor stars
The HERMES spectrograph installed on the 1.2-m Mercator telescope has been used to monitor the radial velocity of 13 low-metallicity carbon stars, among which seven carbon-enhanced metal-poor (CEMP)Expand