A quasi-spherical inner accretion flow in Seyfert galaxies?

We study a phenomenological model for the continuum emission of Seyfert gal axies. In this quasi-spherical accretion scenario, the central X-ray source is constituted of a hot spherical plasma region surrounded by spherically distributed cold dense clouds. The cold material is radiatively coupled wit h the hot thermal plasma. Assuming energy balance, we compute the hard X-ra y spectral slope Gamma and the reflection amplitude R. This simple model en ables us to reproduce both the range of observed hard X-ray spectral slopes and the reflection amplitude R. It also predicts a correlation between R a nd F that is very close to what is observed. Most of the observed spectral variations from source to source would be caused by differences in the clou d covering fraction. If some internal dissipation process is active in the cold clouds, darkening effects may provide a simple explanation for the obs erved distributions of reflection amplitudes, spectral slopes and ultraviol et to X-ray flux ratios.