X- and Gamma-Ray Line Emission Processes
  This chapter is intended to provide a general presentation of the atomic and nuclear processes responsible for X-ray line and gamma-ray line emission in various astrophysical environments. I consider line production from hot plasmas, from accelerated particle interactions, from the decay of radioactive nuclei synthesized in stars and from positron annihilation. Spectroscopic properties of these emissions are discussed in the light of the detection capabilities of modern space instruments. 
Vincent Tatischeff