Related papers: Nucleosynthesis in Early Stars
Two-dimensional simulations of mixing and fall back in non-rotating massive stars have been carried out using realistic initial models for the presupernova star and assuming standard spherically symmetric explosions of 1.2*10^51ergs. Stars…
We observe a sharp transition from a singular, high-mass mode of star formation, to a low-mass dominated mode, in numerical simulations, at a metallicity of 10^-3 Zsolar. We incorporate a new method for including the radiative cooling from…
We present stellar structure and atmosphere models of metal-free stars and examine them from a cosmological point of view. Metal-free stars exhibit high effective temperatures and small sizes relative to metal-enriched stars of equal mass.…
The first generation of stars, often called Population III (or Pop III), form from metal-free primordial gas at redshifts 30 and below. They dominate the cosmic star formation history until redshifts 15 to 20, at which point the formation…
Investigations of elemental abundances in the ancient and most metal deficient stars are extremely important because they serve as tests of variable nucleosynthesis pathways and can provide critical inferences of the type of stars that…
We review recent theoretical results on the formation of the first stars in the universe, and emphasize related open questions. In particular, we discuss the initial conditions for Population III star formation, as given by variants of the…
Using three-dimensional cosmological simulations, we study the assembly process of one of the first galaxies, with a total mass of 10^8 M_sun, collapsing at z = 10. Our main goal is to trace the transport of the heavy chemical elements…
We use the Cambridge stellar evolution code STARS to model the evolution of 5-7 solar mass zero-metallicity stars. With enhanced resolution at the hydrogen and helium burning shell in the AGB phases, we are able to model the entire…
(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,…
A three-dimensional hydrodynamical N-body model for the formation of the Galaxy is presented with special attention to the formation of the bulge component. Starting with cosmologically motivated initial conditions, we obtain a…
We investigate the effect of new stellar models, which take rotation into account, computed for very low metallicities on the chemical evolution of the earliest phases of the Milky Way. We check the impact of these new stellar yields on a…
We examine the role of rotation on the evolution and chemical yields of very metal--poor stars. The models include the same physics, which was applied successfully at the solar $Z$ and for the SMC, in particular, shear diffusion, meridional…
We demonstrate that dark matter interactions can profoundly influence stellar nucleosynthesis in the early universe by altering thermodynamic gradients and modifying nuclear reaction rates within primordial stars. Incorporating a dark…
In cold dark matter cosmological models, the first stars to form are believed to do so within small protogalaxies. We wish to understand how the evolution of these early protogalaxies changes once the gas forming them has been enriched with…
Star formation remains an unsolved problem in astrophysics. Numerical studies of large-scale structure simulations cannot resolve the whole process and their approach usually assumes that only gas denser than a typical threshold can host…
We study the baryonic, chemical and dynamical properties of a significantly large sample of early proto-galaxies in the first 500 Myr of the Universe (redshift z>9), obtained from high-resolution numerical, N-body, hydrodynamical, chemistry…
The first stars were likely more massive than those forming today and thus rapidly evolved, exploding as supernovae and enriching the surrounding gas with their chemical products. In the Local Group, the chemical signature of the first…
Understanding the formation of the first stars is one of the frontier topics in modern astrophysics and cosmology. Their emergence signaled the end of the cosmic dark ages, a few hundred million years after the Big Bang, leading to a…
The chemical abundance patterns of the oldest stars in the Galaxy are expected to contain residual signatures of the first stars in the early universe. Numerous studies attempt to explain the intrinsic abundance scatter observed in some…
We review the current status of knowledge concerning the early phases of star formation during cosmic dawn. This includes the first generations of stars forming in the lowest mass dark matter halos in which cooling and condensation of gas…