Gamma-Ray Line Astrophysics and Stellar Nucleosynthesis: Perspectives for INTEGRAL

Nuclear γ-ray lines constitute the most genuine diagnostic tool of nuclear astrophysics, since they allow for an unambiguous identification of isotopic species. Continuous improvement in instrumentation led to the discovery of several radioactive species in the past 15 years (Al, Co, Co, Ti) in various astrophysical sites (SN1987A and SN1991T, Cas-A, the Milky Way disk). These discoveries boosted theoretical activity on the nucleosynthesis of these radioactive isotopes and on the refined modelling of the corresponding sites, improving our knowledge on stellar evolution, stellar explosions, galactic structure, etc. I review here the current status of γ-ray line astrophysics and present some perspectives related to stellar nucleosynthesis, in view of future missions like INTEGRAL (for more detailed recent reviews see also Prantzos 1996; and Diehl and Timmes 1998).