Measuring ²⁶Al and ⁶⁰Fe in the Galaxy

Abstract

With the SPI high-resolution spectrometer on INTEGRAL, new results have been obtained for long-lived radioactive ²⁶Al and ⁶⁰Fe in our Galaxy: ²⁶Al sources apparently share the pattern of Galactic rotation in the inner Galaxy, and thus allow to estimate a total mass of ²⁶Al in the Galaxy of 2.8M_⊙ from the measured flux. ⁶⁰Fe production in massive stars is constrained by recent gamma-ray detections, and appears to be lower than predicted by standard models. We show the broader implications of these findings both for the study of our Galaxy, and for nucleosynthesis in massive stars.