Superluminal Motion in the Gamma-Ray Blazar 3C 279

Abstract The blazar 3C 279 is one of the strongest extragalactic sources of γ-rays, and is also one of the best studied superluminal radio sources. Definitive testing of models of the broad-band spectral energy distribution, especially in the X-ray and γ-ray regions requires knowledge of the evolution of the spectrum with time. Within the context of the relativistic jet model, multi-wavelength monitoring of the parsec-scale radio jet is also required. We present here the first steps toward such a test, using extensive VLBI monitoring over a 13 year interval at 22 GHz, and γ-ray observations between 1991 and 1996.