Title: Astrophysics with gamma-ray spectroscopy
Speaker: Roland Diehl:  Max Planck Institut fuer extraterrestrische Physik (MPE), and Techn. Univ. Munich, Garching, Germany
Abstract: Gamma rays from nuclear lines are the most-direct astronomical messenger for the
occurrence of nuclear reactions in cosmic sites, next to neutrinos. Characteristic lines
from radioactive decays have been measured with space-borne telescopes, most-recently
with ESA’s INTEGRAL mission, for the isotopes 56Ni, 57Ni, 44Ti, 26Al, and 60Fe.
These span a half-life range from a few days to millions of years. We have learned
about supernova explosion physics (from the shorter-lived species), and about ejecta
transport (from the long-lived ones). Positron annihilation gamma rays have contributed
more and independent information on the latter. Other nuclear lines would be expected,
e.g. from cosmic-ray interactions, but still are lower in intensity than instrumental sensitivities.
In this talk we will discuss the lessons and challenges in context of nucleosynthesis sources
and of properties of our Galaxy.