Estimating Uncertainties in Neutron Capture Rates for 56-Fe and 57-Fe with TALYS

Accurate predictions of elemental abundances in astrophysical environments require reliable neutron-capture reaction rates. Direct experimental measurements are often unavailable, so theoretical models of nuclear level densities (NLDs) are essential inputs for reaction rate calculations. In this work, we present neutron-capture cross-section and astrophysical reaction rate calculations for 56-Fe and 57-Fe using the reaction code TALYS.

We systematically test multiple combinations of NLD models, including shell-model-based NLDs, to estimate uncertainty bands in the resulting cross sections and rates. By comparing these model-dependent results, we assess the impact of NLD choices on predicted reaction rates and provide constraints relevant for nucleosynthesis simulations.