Bonn 2010 – scientific programme

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EP: Fachverband Extraterrestrische Physik

EP 13: Astrophysics II

EP 13.6: Talk

Thursday, March 18, 2010, 15:15–15:30, AKM

Nucleosynthesis in neutrino-driven winds — •Almudena Arcones — Institut für Kernphysik, TU Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt, Germany — GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, 64291 Darmstadt, Germany

The specific mechanism and astrophysical site for the production of half of the heavy elements, the so-called r-nuclei, remains to be found. We address the problem aking improvements along two main fronts: the astrophysical environment and the properties of the nuclei far from stability. Observational data indicate that there are two components. The heavy r-process nuclei (A>130) are produced by rapid neutron capture in a yet unknown site. The other component corresponds to the "lighter heavy nuclei" or weak r-process. These nuclei are produced by charge-particle reactions (CPR) in what it was also known as light element primary process (LEPP). Our nucleosynthesis studies are based on trajectories of hydrodynamical simulations for core-collapse supernovae and their subsequent neutrino-driven winds. We show for the first time that CPR elements can be produced in neutrino-driven winds and we relate their abundances to the neutrino emission from the nascent neutron star. Based on the latest hydrodynamical simulations, heavy r-process elements cannot be synthesized in the neutrino-driven winds. However, by artificially increasing the wind entropy, elements up to A=195 can be made. In this way one can mimic the general behavior of an ejecta where the r-process occurs. We use this approach to study the impact of the nuclear physics input and of the long-time dynamical evolution on the final abundances.