Radiogenic p-isotopes from type Ia supernova, nuclear physics uncertainties, and galactic chemical evolution compared with values in primitive meteorites

The nucleosynthesis of proton-rich isotopes is calculated for multi-dimensional Chandrasekhar-mass models of Type Ia supernovae (SNe Ia) with different metallicities. The predicted abundances of the short-lived radioactive isotopes 92Nb, 97, 98Tc, and 146Sm are given in this framework. The abundance seeds are obtained by calculating s-process nucleosynthesis in the material accreted onto a carbon-oxygen white dwarf from a binary companion. A fine grid of s-seeds at different metallicities and 13C-pocket efficiencies is considered. A galactic chemical evolution model is used to predict the contribution of SN Ia to the solar system p-nuclei composition measured in meteorites. Nuclear physics uncertainties are critical to determine the role of SNe Ia in the production of 92Nb and 146Sm. We find that, if standard Chandrasekhar-mass SNe Ia are at least 50% of all SN Ia, they are strong candidates for reproducing the radiogenic p-process signature observed in meteorites.Peer reviewedFinal Accepted Versio

The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars Project - Status and Prospects

The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars) project is an astrophysical online database for cross sections relevant for nucleosynthesis in the s process and the γ process. The s-process database (http://www.kadonis.org) was started in 2005 and is presently facing its 4th update (KADoNiS v1.0). The γ-process database (KADoNiS-p, http://www.kadonis.org/pprocess) was recently revised and re-launched in March 2013. Both databases are compilations for experimental cross sections with relevance to heavy ion nucleosynthesis. For the s process recommended Maxwellian averaged cross sections for kT=5-100 keV are given for more than 360 isotopes between 1H and 210Bi. For the γ-process database all available experimental data from (p, γ), (p, n), (p, α), (α, γ), (α, n), and (α, p) reactions between 70Ge and 209Bi in or close to the respective Gamow window were collected and can be compared to theoretical predictions. The aim of both databases is a quick and user-friendly access to the available data in the astrophysically relevant energy regions. © 2014 Elsevier Inc.Peer reviewe

A thin film model for corotational Jeffreys fluids under strong slip

We derive a thin film model for viscoelastic liquids under strong slip which obey the stress tensor dynamics of corotational Jeffreys fluids.Comment: 3 pages, submitted to Eur. Phys. J.

Production of 92Nb, 92Mo, and 146Sm in the gamma-process in SNIa

The knowledge of the production of extinct radioactivities like 92Nb and 146Sm by photodisintegration processes in ccSN and SNIa models is essential for interpreting abundances in meteoritic material and for Galactic Chemical Evolution (GCE). The 92Mo/92Nb and 146Sm/144Sm ratios provide constraints for GCE and production sites. We present results for SNIa with emphasis on nuclear uncertainties.Comment: 6 pages, 4 figures, Proceedings of the 13th Symposium on Nuclei in the Cosmos (NIC XIII), July 2014, Debrecen, Hungar

Testing the role of SNe Ia for galactic chemical evolution of p-nuclei with two-dimensional models and with s-process seeds at different metallicities

Date of Acceptance: 07/11/2014The bulk of p isotopes is created in the "gamma processes" mainly by sequences of photodisintegrations and beta decays in explosive conditions in Type Ia supernovae (SNIa) or in core collapse supernovae (ccSN). The contribution of different stellar sources to the observed distribution of p-nuclei in the solar system is still under debate. We explore single degenerate Type Ia supernovae in the framework of two-dimensional SNIa delayed-detonation explosion models. Travaglio et al. discussed the sensitivity of p-nuclei production to different SNIa models, i.e., delayed detonations of different strength, deflagrations, and the dependence on selected s-process seed distributions. Here we present a detailed study of p-process nucleosynthesis occurring in SNIa with s-process seeds at different metallicities. Based on the delayed-detonation model DDT-a of TRV11, we analyze the dependence of p-nucleosynthesis on the s-seed distribution obtained from different strengths of the 13C pocket. We also demonstrate that 208Pb seed alone changes the p-nuclei production considerably. The heavy-s seeds (140 ≤A < 208) contribute with about 30%-40% to the total light-p nuclei production up to 132Ba (with the exception of 94Mo and 130Ba, to which the heavy-s seeds contribute with about 15% only). Using a Galactic chemical evolution code from Travaglio et al., we study the contribution of SNIa to the solar stable p-nuclei. We find that explosions of Chandrasekhar-mass single degenerate systems produce a large amount of p-nuclei in our Galaxy, both in the range of light (A ≤ 120) and heavy p-nuclei, at almost flat average production factors (within a factor of about three). We discussed in details p-isotopes such as 94Mo with a behavior diverging from the average, which we attribute to uncertainties in the nuclear data or in SNIa modeling. Li et al. find that about 70% of all SNeIa are normal events. If these are explained in the framework of explosions of Chandrasekhar-mass white dwarfs resulting from the single-degenerate progenitor channel, we find that they are responsible for at least 50% of the p-nuclei abundances in the solar system.Peer reviewedFinal Accepted Versio

Nuclear Aspects of Nucleosynthesis in Massive Stars

Preliminary results of a new set of stellar evolution and nucleosynthesis calculations for massive stars are presented. These results were obtained with an extended reaction network up to Bi. The discussion focuses on the importance of nuclear rates in pre- and post-explosive nucleosynthesis. The need for further experiments to study specific reactions and nuclear properties (optical alpha+nucleus potentials) is emphasized.Comment: 6 pages, 2 figures; invited talk, to appear in the Proceedings of the Int. Conf. "Structure of the Nucleus at the Dawn of the Century", May 2000, Bologna, Ital

Nucleosynthesis in massive stars revisited

We have performed the first calculations to follow the evolution of all stable nuclei and their radioactive progenitors in a finely-zoned stellar model computed from the onset of central hydrogen burning through explosion as a Type II supernova. Calculations were done for 15, 20, and 25 solar masses Pop I stars using the most recently available set of experimental and theoretical nuclear data, revised opacity tables, and taking into account mass loss due to stellar winds. Here results are presented for one 15 solar masses model.Comment: 4 pages, 1 figure; needs espcrc1.sty; talk at "Nuclei in the Cosmos 2000", Aarhus, Denmark, June 2000; will appear in Nucl. Phys.

Thermal noise influences fluid flow in thin films during spinodal dewetting

Experiments on dewetting thin polymer films confirm the theoretical prediction that thermal noise can strongly influence characteristic time-scales of fluid flow and cause coarsening of typical length scales. Comparing the experiments with deterministic simulations, we show that the Navier-Stokes equation has to be extended by a conserved bulk noise term to accomplish the observed spectrum of capillary waves. Due to thermal fluctuations the spectrum changes from an exponential to a power law decay for large wavevectors. Also the time evolution of the typical wavevector of unstable perturbations exhibits noise induced coarsening that is absent in deterministic hydrodynamic flow.Comment: 4 pages, 3 figure