Cosmic rays from regions of star formation. III

On the basis of COS-B observations (Wills, 1980), it has been proposed that CR acceleration within the Rho Oph cloud complex (ROCC) is required to account for its gamma-ray luminosity (Casse and Paul, 1980, Bignami and Morfill, 1980). However, Issa et al. (1980) have suggested that the size of the ROCC has been underestimated by a factor approximately= 2, and that the cloud mass is a factor approximately= 4 higher than given by Myers et al. (1978), making unnecessary CR acceleration and trapping in the cloud interior. Counter arguments are presented confirming the picture depicted by Myers et al. (1978) and hence the necessity of CR acceleration in the cloud. The gamma-ray emission of the ROCC likely results from CR interactions with the cloud material. CR would be accelerated at the boundary between supersonic stellar winds and the circumstellar medium, with T-Tauri stars substantially contributing to the acceleration by releasing mechanical power. (Auth.)