We compare total flux density (TFD) variations in 27 γ-bright blazars with structural changes in their parsec-scale jets using multi-epoch VLBA observations at 22 and 43 GHz together with data from the Metsähovi quasar monitoring program. There is a clear connection between TFD outbursts and VLBI components emerging into the jet. The ejections of the VLBI components are coincident with the beginning times of the TFD flares, and they also show similar flux evolution. Our results suggest that all radio variations are related to shocks propagating in the jet. In our sources, a large fraction of the shocks seem to grow and decay within the innermost few tenths of a milliarcsecond of the radio core. Therefore, we see them only as so-called ``core flares'' in the VLBI images.
|Title of host publication||High Energy Blazar Astronomy, ASP Conference Series|
|Publication status||Published - 2003|
|MoE publication type||B3 Non-refereed article in conference proceedings|