The Role of Rotation on the Yields of the Two γ-Ray Emitters ²⁶Al and ⁶⁰Fe Ejected by Massive Stars

We show that the observed 60 Fe/ 26 Al 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 nonrotating stellar models yield 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 M. Limongi & A. Chieffi, complemented by additional ones fully consistent with the original grid, allowing a finer resolution in the initial rotational velocity distribution.