Compton-synchrotron models for the nucleus of Centaurus A (NGC 5128)

Compton-synchrotron models are constructed to account for the observed microwave through X-ray spectrum and the recently reported flux of γ-rays with E/sub gamma/approximately-greater-than3times1011 eV from NGC 5128 (Cen A). The spectrum suggests a double source structure in the nucleus of NGC 5128. The γ-rays arise from inverse Compton scattering of a synchrotron photon spectrum that must extend through X-ray energies. The observed γ-ray flux and the self-absorbed synchrotron spectra determine the source angular sizes, energy densities, and magnetic fields. Such parameters for the sources in the nuclei of active galaxies may enable the eventual description of the source mechanisms. Further implications of the model and possible observations are discussed. (auth)