Name of the Speaker(s): Vicente, L., Charlot., and Sol, H.
Institution: (DARC) Observatoire de Meudon
Title of the communication: VLBI maps of a sample of blazars from geodetic data
Preliminary abstract (12 lines max.):
Multi-epoch VLBI maps of nine blazars have been produced from 8.4 and 2.3~GHz geodetic data acquired by the Crustal Dynamics Program. We discuss the parsec-scale structure of these blazars, some of which have not been previously mapped with VLBI. Apparent jet component velocities and spectral indices are estimated. A detailed study of the BL~Lac object OJ287 is presented, based on ten successive 8.4~GHz maps at intervals of a few months. This intensive monitoring suggests that the radio knots in the VLBI jet of OJ287 move along a helical trajectory.