Related papers: Advances in s-process models

Context: It is well known that the so-called s-process is responsible for the production of neutron-rich trans-iron elements, that form the bulk of the "heavy nuclides" (i.e. nuclides more massive than the iron-group nuclei) in the…

Several stars at the low-metallicity extreme of the Galactic halo show large spreads of [Pb/hs]. Theoretically, a s-process pattern should be obtained from an AGB star with fixed metallicity and initial mass. For the third dredge-up and the…

Barium stars are one of the important probes to understand the origin and evolution of slow neutron-capture process elements in the Galaxy. These are extrinsic stars, where the observed s-process element abundances are believed to have an…

In a previous paper we compared the SEDs of a sample of 808 K+A galaxies from the FUV to the MIR to the predictions of the spectrum synthesis models explicitly using AGB components. Here we use the new AGB-light models from C. Maraston…

Context: Our understanding of the s-process nucleosynthesis in asymptotic giant branch (AGB) stars is incomplete. AGB models predict, for example, large overabundances of lead (Pb) compared to other s-process elements in metal-poor low-mass…

We follow the chemical evolution of the Galaxy for elements from Ba to Eu, using an evolutionary model suitable to reproduce a large set of Galactic (local and non local) and extragalactic constraints. Input stellar yields for neutron-rich…

A recent survey of a large sample of Galactic intermediate-mass (>3 Msun) asymptotic giant branch (AGB) stars shows that they exhibit large overabundances of rubidium (Rb) up to 100--1000 times solar. These observations set constraints on…

The slow neutron capture process in massive stars (the weak s-process) produces most of the s-only isotopes in the mass region 60 < A < 90. The nuclear reaction rates used in simulations of this process have a profound effect on the final…

Uncertainties in nucleosynthesis models originating from uncertainties in astrophysical reaction rates were estimated in a Monte Carlo variation procedure. Thousands of rates were simultaneously varied within individual,…

We present new spectroscopic observations for a sample of C(N)-type red giants. These objects belong to the class of Asymptotic Giant Branch stars, experiencing thermal instabilities in the He-burning shell (thermal pulses). Mixing episodes…

We report the first spectroscopic identification of massive Galactic asymptotic giant branch (AGB) stars at the beginning of the thermal pulse (TP) phase. These stars are the most Li-rich massive AGBs found to date, super Li-rich AGBs with…

We follow the static abundance profiles of the C, N, O, Ne, Na, Mg, and Al isotopes around the hydrogen-burning shell (H shell) of globular cluster red-giant-branch (RGB) stellar models in order to study the observed abundance anomolies…

The abundances of the slow neutron-capture (s-) process elements observed in barium stars can be explained by considering mass transfer in a binary system from an asymptotic giant branch (AGB) star onto a smaller mass and less evolved…

We follow the Galactic enrichment of three easily observed light n-capture elements Sr,Y,and Zr.Input stellar yields have been first separated into their respective main and weak s-process,and r-process components.The s-process yields from…

We report the abundances of neutron-capture elements in eight carbon-rich, metal-poor (-2.7=<[Fe/H]=<-1.9) stars observed with the Subaru Telescope High Dispersion Spectrograph. The derived abundance patterns indicate that the…

Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations demonstrate that the earliest generations of stars in the Galaxy,…

Recent observations of heavy elements in Globular Clusters reveal intriguing deviations from the standard paradigm of the early galactic nucleosynthesis. If the r-process contamination is a common feature of halo stars, s-process…

About half of the elements beyond iron are synthesized in stars by rapid-neutron capture process (r-process). The stellar environment provides very high neutron flux in a short time ($\sim$ seconds) which is conducive for the creation of…

The triple alpha process plays an important role in the production of 12C in stars. Its rate is known with an accuracy of about 12%. We examine the corresponding uncertainties introduced in the description of pre-supernova stars, of…

We present new theoretical stellar yields and surface abundances for three grids of metal-rich asymptotic giant branch (AGB) models. Post-processing nucleosynthesis results are presented for stellar models with initial masses between…