Physical information derived from the internal structure in jets
  We present the first results on the analysis of the structures observed in the jet of the quasar 0836+710. We obtain the ridge lines of the jet at different epochs and several frequencies. We interpret the oscillatory structures obtained as waves that can be attached to the growth of instabilities. We explain how to derive information on the nature and origin of these structures by fitting together the ridge lines at different epochs and frequencies. Finally we show the predictive power of this approach: by generating an artificial wave and applying the corresponding relativistic and projection effects we show that apparent changes in the jet direction in the inner regions of jets can be attached to the transversal motion of structures. 
M. Perucho, A.P. Lobanov, Y.Y. Kovalev