DELAY MAPPING OF THE SCATTERING MEDIUM IN ACTIVE GALACTIC NUCLEI

The Stokes parameters of Thomson-scattered radiation originating from a variable primary source are computed in a geometry appropriate to the immediate surroundings of AGNs. The time dependent problem is solved in terms of transfer functions, and the time behaviour of the polarization degree and position angle is exemplified for an assumed light curve of the primary source. Our results are compared with the data available for a set of Seyfert 1 galaxies, and for a polarized outburst of NGC 4151. Limits are derived on the distribution and optical depth of a scattering medium.