Production of Light Element Primary Process nuclei in neutrino-driven winds

TL;DR

This paper compares observed light element abundances in ultra metal poor stars with nucleosynthesis models from supernova neutrino-driven winds, showing the models can explain the LEPP pattern.

Contribution

It demonstrates that neutrino-driven wind simulations can reproduce the observed LEPP element pattern in ultra metal poor stars, exploring the impact of electron fraction variations.

Findings

Neutrino-driven wind models can explain LEPP element abundances.

The LEPP pattern can be reproduced in both proton- and neutron-rich conditions.

Abundance predictions are sensitive to the electron fraction parameter.

Abstract

We present first comparisons between Light Element Primary Process (LEPP) abundances observed in some ultra metal poor (UMP) stars and nucleosynthesis calculations based on long-time hydrodynamical simulations of core-collapse supernovae and their neutrino-driven wind. UMP star observations indicate Z>38 elements include the contributions of at least two nucleosynthesis components: r-process nuclei that are synthesized by rapid neutron capture in a yet unknown site and LEPP elements (mainly Sr, Y, Zr). We show that neutrino-driven wind simulations can explain the observed LEPP pattern. We explore in detail the sensitivity of the calculated abundances to the electron fraction, which is a key nucleosynthesis parameter but poorly known due to uncertainties in neutrino interactions and transport. Our results show that the observed LEPP pattern can be reproduced in proton- and neutron-rich winds.