X-rays and γ-rays from Supernova 1987a

The observation of X-rays and γ-rays from SN 1987a can provide important constraints on parameters for models of this unique event. We present the results of detailed Monte Carlo calculations of the fluxes to be expected in several X-ray bands and for the strong line at 847 keV associated with the decay of 56Co. Our calculations use Model 10H of Woosley, Pinto, and Ensman(1988), with 0.075M ⊙ of radioactive material. If it is assumed that there is no mixing of this material with the layers above, then the X-ray fluxes do not become detectable as early as the observations made by the Ginga team in August, 1987. If these observations correspond to X-rays arising from γ-rays Compton scattered down in energy in the supernova ejecta, rather than the interaction of the ejecta with circumstellar matter, then they can only be explained by mixing outward of radioactive material or an envelope with some combination of less mass or greater kinetic energy per unit mass.