Abstract

Here is presented a statistical test for the accretion disc model. The effect of different inclinations of the disc to the line of sight is shown. Then the possibility that the ratio R of the radio core luminosity to the radio lobe luminosity is a good orientation indicator is investigated. It is shown that R. describes the intrinsic power of the central radio source.

A statistical test of the accretion disc model

The model adopted here is that, described by Collin and Dumont (1989), of an accretion disc illuminated by the central nonthermal source. The disc emits in its inner part the UV and optical continuum, and in its outer parts the low ionization lines (LIL; e.g., the Balmer lines) as proposed by Collin (1987). A second region emits the high ionization lines (HIL; e.g., Lα and CIV); it can have a spherical geometry. Both regions are illuminated by the central source. For the disc, illumination occurs through backscattering of the nonthermal radiation by a hot medium (halo). This model has been worked out by Dumont and Joly (1992).

Using the code of Dumont and Collin (1990) we have computed the line spectrum emitted by the illuminated disc as a function of the central source luminosity, the Eddington ratio (Lbol\LEdd) and the characteristics of the scattering halo (density structure and optical thickness).