Low and medium energy gamma-ray astronomy — present status and future aspects

摘要: Abstract During the last few years quite some progress has been achieved in field of low and medium energy gamma-ray astronomy below about 30 MeV. Gamma rays from galactic center anti-center region have detected, which require a high interstellar electron flux 100 MeV range, if they are predominantly diffuse nature. Though Crab pulsar its nebula still only sources definitely recently determined upper limits to fluxes other radio pulsars close theoretically expected values. Active galaxies seem maximum luminosity range between several keV and, therefore, special interest. First observational results reported on Seyfert NGC 4151 MCG 8-11-11, galaxy CenA. The nature cosmic component at energies is not yet solved. Unresolved active good candidates for origin. Considering present status gamma ray study like unidentified sources, Milky Way as whole, sky be prime targets broad band observations GRO area. An unexplored that astronomy, however, always open surprises.