X-ray spectra transmitted through matter which is optically thick to Compto
n scattering are computed by means of Monte Carlo simulations. Applications
to the BeppoSAX data of the Seyfert 2 galaxy in Circinus, and to the spect
ral modeling of the Cosmic X-ray Background, are discussed. (C) 1999 Elsevi
er Science B.V. All rights reserved.