This volume consists of invited lectures and seminars presented at the NATO Advanced Study Institute "The Gamma Ray Sky with COMPTON GRO and SIGMA," which was held at the Centre de Physique Theorique of Les Houches (France) in January / February 1994. The school has been planned by a Scientific Organizing Committee. It was organized with the aim of providing students and young researchers with an up-to-date account of the high-energy phenomena in the vicinity of compact objets and the diffuse gamma-ray backgrounds after the early results from the gamma-ray telescope SIGMA and the four...

Evry SCHATZMAN Radio-Astronomie, E. N. S. , Paris, France The recent developments of the Supernova theory and numerical relativity can lead in the near future to an understanding of gravitational collapse and to a reliable prediction of the amplitude of the gravitational waves generated during neutron star formation. These prospects explain the great interest which has developed in the international scientific community for the workshop. We were financially limited in the number of guests and participants and we apologize for not having been able to gather all the specialists actually...

Evry SCHATZMAN Radio-Astronomie, E. N. S. , Paris, France The recent developments of the Supernova theory and numerical relativity can lead in the near future to an understanding of gravitational collapse and to a reliable prediction of the amplitude of the gravitational waves generated during neutron star formation. These prospects explain the great interest which has developed in the international scientific community for the workshop. We were financially limited in the number of guests and participants and we apologize for not having been able to gather all the specialists actually...