# Reducing Uncertainties in the Production of the Gamma Emitting Nuclei 26Al, 44Ti, and 60Fe in Core Collapse Supernovae by Using Effective Helium Burning Rates

## TL;DR

This study uses effective helium burning reaction rates to improve predictions of gamma-emitting nuclei yields in supernovae, reducing uncertainties and analyzing the impact of failed supernovae on these yields.

## Contribution

It introduces the use of effective reaction rates to decrease yield prediction uncertainties and assesses the influence of failed supernovae on isotope yields.

## Key findings

- Reduced yield uncertainties compared to previous models
- Failed supernovae significantly lower isotope yields
- Predicted 60Fe/26Al ratio remains stable but exceeds observed values

## Abstract

We have used effective reaction rates (ERR) for the helium burning reactions to predict the yield of the gamma-emitting nuclei 26Al, 44Ti, and 60Fe in core col- lapse supernovae. The variations in the predicted yields for values of the reaction rates allowed by the ERR are much smaller than obtained previously, and smaller than other uncertainties. A "filter" for supernova nucleosynthesis yields based on pre-supernova structure was used to estimate the effect of failed supernovae on the initial mass function-averaged yields; this substantially reduced the yields of all these isotopes, but the predicted yield ratio 60Fe/26Al was little affected. The robustness of this ratio is promising for comparison with data, but it is larger than observed in nature; possible causes for this discrepancy are discussed.