Gamma-Ray Line Astrophysics: Yesterday, Now, and Then

Dr. Thomas Siegert

University of California San Diego

Measurements in the 'MeV gap' are cumbersome, dominated by instrumental background, and often merely descriptive. Astrophysical nuclear de-excitation lines therefore receive hardly any attention. They however have the potential to provide deep insights to many unsolved problems in stellar evolution, Galactic dynamics and feedback, cosmic-ray acceleration and propagation, stellar flares and atmospheres, as well as dark matter and cosmology in general. After half a century, gamma-ray line astrophysics is now escaping its infancy with future-oriented instrumentation towards high-precision measurements. In this talk, I will give a brief historical overview and reveal the unused potential of MeV lines with the example of supernova observations.