Related papers: Supernova Nucleosynthesis in the Early Universe
Recent studies suggest that metal-poor stars enhanced in carbon but containing low levels of neutron-capture elements may have been among the first to incorporate the nucleosynthesis products of the first generation of stars. We have…
Neutron-star mergers were recently confirmed as sites of rapid-neutron-capture (r-process) nucleosynthesis. However, in Galactic chemical evolution models, neutron-star mergers alone cannot reproduce the observed element abundance patterns…
Big Bang nucleosynthesis produces only light elements and the very first generation stars are thus formed from metal-free clouds. They start the production of heavy elements during their life, and enrich the interstellar medium through…
The first stars hold intrinsic interest for their uniqueness and for their potential importance to galaxy formation, chemical enrichment, and feedback on the intergalactic medium (IGM). The metal-free composition of the first stars…
The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of the chemical evolution of the Galaxy. In particular, these stars allow us to study the formation and evolution of the elements…
We reconsider the model of neutrino production during the 'bright phase', first suggested in 1977, in the light of modern understanding of the role of Pop III stars and acceleration of particles in supernova shocks. We concentrate on the…
The first stars fundamentally transformed the early Universe through their production of energetic radiation and the first heavy chemical elements. The impact on cosmic evolution sensitively depends on their initial mass function (IMF),…
We investigate the transition from primordial Population III (Pop III) star formation to normal Pop II star formation in the first galaxies using new cosmological hydrodynamic simulations. We find that while the first stars seed their host…
We present a three-component mixing model for the evolution of O abundance relative to Fe, taking into account the contributions of the first very massive (> 100 solar masses) stars formed from Big Bang debris. We show that the observations…
(Abridged) The CEMP--no stars are "carbon-enhanced-metal-poor" stars that in principle show no evidence of s-- and r--elements from neutron captures. We try to understand the origin and nucleosynthetic site of their peculiar CNO, Ne--Na,…
The first Pop III stars formed out of primordial, metal free gas, in minihalos at z>20, and kickstarted the cosmic processes of reionizaton and enrichment. While these stars are likely more massive than their enriched counterparts, the…
The cores of stars are the cosmic furnaces where light elements are fused into heavier nuclei. The fusion of hydrogen to helium initially powers all stars. The ashes of the fusion reactions are then predicted to serve as fuel in a series of…
Models of star formation in the early universe depend on the details of accretion, fragmentation and radiative feedback. Different simulations predict different initial mass functions of the first stars, ranging from predominantly low mass…
Low-metallicity stars preserve the signatures of the first stellar nucleosynthesis events in the Galaxy, as their surface abundances reflect the composition of the interstellar medium from which they were born. Aside from primordial Big…
The first stars are assumed to be predominantly massive. Although, due to the low initial abundances of heavy elements the line-driven stellar winds are supposed to be inefficient in the first stars, these stars may loose a significant…
To constrain the properties of the first stars with the chemical abundance patterns observed in metal-poor stars, one must identify any non-trivial effects that the hydrodynamics of metal dispersal can imprint on the abundances. We use…
LTE abundances of light elements in extremely metal-poor (EMP) stars have been previously derived from high quality spectra. New derivations, free from the NLTE effects, will better constrain the models of the Galactic chemical evolution…
The metal-free (Pop. III) and extremely metal-poor (EMP) stars of low- and intermediate-masses experience mixing of hydrogen into the helium convection during the early TP-AGB phase, differently from the meal-rich stars. We study the…
We study cosmological simulations of early structure formation, including non-equilibrium molecular chemistry, metal pollution from stellar evolution, transition from population III (popIII) to population II (popII) star formation,…
We present a detailed comparison between an extended set of elemental abundances observed in some of the most metal poor stars presently known and the ejecta produced by a generation of primordial core collapse supernovae. We used five…