Production of light trans-Fe elements in core collapse-supernovae: Implications from presolar SiC-X grains

We have extended our large-scale nucleosynthesis parameter study within the high-entropy-wind (HEW) scenario of core-collapse supernovae (cc-SNe), which began a decade ago with the primary aim to obtain indications for the production of classical ‘p-only’ isotopes of the light trans-Fe elements in the Solar System (S.S.). Here, we focus on the nucleosynthetic interpretation of the anomalous isotopic compositions of Zr, Mo and Ru in presolar SiC-X grains. We show that these meteoritic observations do not represent the signatures of a ‘clean’ stellar source, but rather are mixtures of an exotic nucleosynthesis component with S.S. material. Furthermore, we confirm our earlier results that all stable p-, s- and r-isotopes of Zr, Mo and Ru are co-produced by moderately neutron-rich ejecta of the low-entropy, charged-particle component of Type II cc-SNe. The synthesis of these isotopes by a ‘primary’ production mode provides further means to revise the abundance estimates of the light trans-Fe elements from currently favored secondary nucleosynthesis scenarios like Type Ia SNe or neutron-bursts in exploding massive stars.