1998A&A...334..489O

Broad-band (gamma to radio) variations of the flux density were observed in the first half of 1992 in the luminous high redshift (z=2.172) quasar S5 0836+710. VLBI monitoring observations during 1993-1996 performed at 86GHz, 22GHz, 15GHz, and 8GHz show the ejection of a new jet component, which most probably is directly related to a quasi simultaneous gamma-, X-ray, optical flaring activity which was observed in February 1992. During the period 1992-1993 the flaring propagated through the radio spectrum. From several quasi-simultaneous radio spectra taken during this phase of activity, we determine the time evolution of the spectral turnover of the radio spectrum in the S_m-ν_m diagram. The data indicate a correlation of the jet activity with the variability of the broad-band electromagnetic spectrum of the source. The observational findings are discussed in the framework of relativistic shock models.