Nucleosynthesis and Gamma-Ray Line Spectroscopy with INTEGRAL

Cosmic nucleosynthesis co-produces unstable isotopes, which emit characteristic gamma-ray emission lines upon their radioactive decay that can be measured with SPI on INTEGRAL. High spectral resolution allows to derive velocity constraints on nucleosynthesis ejecta down to ' 100 km s−1. Supernova explosions generate gamma-rays from radioactive decays of 56Ni and 44Ti, which can reveal details of the explosion mechanism. Core-collapse supernovae ap-parently do not always produce significant amounts of 44Ti, as in the Galaxy fewer sources than expected from the supernova rate have been found. INTEGRAL’s 44Ti data on the well-observed Cas A and SN1987A events are evidence that non-spherical explosions and 44Ti production may be correlated. INTEGRAL may have the chance to see directly for a SNIa the 56Ni decay chain which powers the supernova light curve: SN2011fe at only 6.4 Mpc distance may be close enough. Characteristic gamma-ray lines from radioactive decays of long-lived 26Al and 60Fe isotopes have been exploited to obtain information on the structure and dynamics of massive stars in their late evolution and supernovae, as their yields are sensitive to those details. The extended INTE-GRAL mission establishes a database of sufficiently-deep observations of several specific regions of massive star groups, such as Cygnus, Carina, and Sco-Cen. In the inner Galaxy, 26Al nucle