The crab and cygnus a as gamma ray sources

Abstract

The Crab is estimated to give a maximum nuclear γ-ray flux of 10−2 cm−2 s−1 from the decay of251Cf formed with253Cf during the supernova outburst. Although extrapolation of the radio and visual fluxes suggests the possibility of a flux as high as 10 γ cm−2 s−1 between 1 and 2 MeV, model calculations suggest that 7·10−5 γ cm−2 s−1 above about 10 MeV is more probable. Bremsstrahlung and Compton scattering yield considerably lower fluxes. Cygnus A, regarded as the result of a collision of matter and antimatter, should yield lower fluxes than the γ cm−2 s−1 estimated by Morrison. The radio flux suggests a π0 decay γ-flux of 4·10−5 γ cm−2 s−1. ForE>10 MeV, any γ-ray flux exceeding 5·10−5 γ cm−2 s−1 should be detectable from a balloon flown emulsion stack.