The role of rotation on the yields of the two {\gamma}-ray emitters 26Al and 60Fe ejected by massive stars

TL;DR

This paper demonstrates that including stellar rotation in models is essential to accurately reproduce the observed gamma-ray flux ratio of 60Fe to 26Al emitted by massive stars, highlighting rotation's significant impact on stellar yields.

Contribution

It introduces improved stellar models that incorporate rotation, providing more accurate predictions of gamma-ray emitter yields compared to non-rotating models.

Findings

Rotating models match the observed 60Fe/26Al flux ratio (0.24)

Non-rotating models significantly underestimate the ratio (0.062)

Enhanced models use a finer resolution of initial rotational velocities

Abstract

We show that the observed 60Fe/26Al flux ratio provided by the SPectrometer on INTEGRAL satellite (0.24 +- 0.04) can be reproduced only if rotation is taken into account in the computation of the stellar models. Predictions from non-rotating stellar models yield to a significantly lower ratio (0.062), which is incompatible with the observed value. The adopted models and the associated yields are based on a combination of models already published by Limongi & Chieffi (2018) complemented by additional ones fully consistent with the original grid, allowing a finer resolution in the initial rotational velocity distribution.