Related papers: Galactic chemical evolution of Ba-peak elements
A population number synthesis code follows in detail the evolution of a population of single stars and of close binaries. We use our code to simulate the population of neutron star - neutron star and black hole - neutron star binaries. We…
The evolving galaxy is considered as a system of baryonic fragments embedded into the static dark nonbaryonic (DH) and baryonic (BH) halo and subjected to gravitational and viscous interactions. Though the chemical evolution of each…
We present an abundance analysis based on high resolution spectra of 10 stars selected to span the full range in metallicity in the Ursa Minor dwarf spheroidal galaxy. We find [Fe/H] for the sample stars ranges from -1.35 to -3.10 dex and…
We outline the results of a study of the chemical composition of 14 stars in the Sagittarius dwarf spheroidal galaxy (Sgr dSph). For the Sgr dSph stars with [Fe/H]>-1 the abundances are highly unusual, showing a striking enhancement in…
There is now strong evidence that some stars have been born with He mass fractions as high as $Y \approx 0.40$ (e.g., in $\omega$ Centauri). However, the advanced evolution, chemical yields, and final fates of He-rich stars are largely…
Standard models for the chemical evolution of the Galaxy are reviewed with particular emphasis on the history of the abundance gradients in the disk. The effects on the disk structure and metallicity of gas accretion are discussed, showing…
The supernova yields of several heavy elements including alpha-, iron-group, and r-process elements are obtained as a function of the mass of their progenitor main-sequence stars M_ms from the abundance patterns of extremely metal-poor…
Globular clusters (GCs) are key to understanding the formation and evolution of our Galaxy. While the abundances of light and Fe-peak elements in GCs have been widely studied, investigations into heavier, neutron-capture elements -- and…
In past decades a lot of progress has been made towards understanding the main s-process component that takes place in thermally pulsing Asymptotic Giant Branch (AGB) stars. During this process about half of the heavy elements, mainly…
Abundances of N, Si, S, and Fe for 45 damped Lyman alpha systems (DLAs) have been compiled and detailed one-zone chemical evolution models have been constructed for 30 of them. Assuming continuous star formation, we found that final…
The supernovae SN II & Ib/c make major stellar nucleosynthetic contributions to the inventories of the stable nuclides during the chemical evolution of the galaxy. A case study is performed here with the help of recently developed numerical…
The chemical evolution of the Galactic bulge is treated here in the context of an inside-out model for the Galaxy formation. We assume that this central region evolved even faster than the Galactic halo and test the effect of changing the…
We present models for the slow neutron-capture process (s process) in asymptotic giant branch (AGB) stars of metallicity [Fe/H]=-2.3 and masses 0.9 Msun to 6 Msun. We encountered different regimes of neutron-capture nucleosynthesis…
The study of the chemical composition of Planetary Nebulae in external galaxies is of paramount importance in the fields of stellar evolution and of the chemical enrichment history of galaxies. In the last years a number of spectroscopic…
Light and intermediate nuclei as well as s-process elements have been detected in presolar grains and in evolved red giants. The abundances of some of these nuclei cannot be accounted for by canonical stellar models and require…
We investigate the enrichment of europium, as a representative of r-process elements, in the Galactic halo. In present chemical evolution models, stars are assumed to be formed through shock processes by supernovae (SNe). The enrichment of…
To better characterize the abundance patterns produced by the r-process, we have derived new abundances or upper limits for the heavy elements zinc (Zn), yttrium (Y), lanthanum (La), europium (Eu), and lead (Pb). Our sample of 161…
We study the chemical evolution of Zr, La, Ce and Eu in the Milky Way discs and bulge by means of chemical evolution models compared with recent spectroscopic data. We consider detailed chemical evolution models for the Galactic thick disc,…
We explore modifications to the current scenario for the slow neutron capture process in asymptotic giant branch (AGB) stars to account for the Pb deficiency observed in post-AGB stars of low metallicity ([Fe/H] ~ -1.2) and low initial mass…
The enrichment history of heavy neutron-capture elements in the Milky Way disc provides fundamental information about the chemical evolution of our Galaxy and about the stellar sources that made those elements. In this work we give new…