Name of the Speaker(s): Anne Lahteenmaki
Institution: Metsahovi Radio Research Station
Title of the communication: Doppler boosting factors and viewing angles for different classes of AGN derived from continuum and VLBI observations
Preliminary abstract: Two intrinsic parameters determining the appearance of an AGN are the speed of the jet flow and the viewing angle. These can be calculated if the apparent superluminal speed and the Doppler boosting factor D are known. D is usually estimated from the SSC X-ray flux, but the derived values are notoriously uncertain. We explore alternative ways of estimating D from total flux density variations associated with the creation of new VLBI components, and use the derived values to calculate the intrinsic Lorentz factors and viewing angles of various classes of AGN. The resulting source parameters are compared with those based on SSC calculations. We argue that the values derived from flux density variations are much more accurate and realistic than the SSC-derived ones usually presented.