The standard model for apparent superluminal motion is that of relativistic motion in a jet pointed nearly along the line of sight. Variants of this model give a natural explanation for the extremely asymmetric morphology observed in the radio cores of these sources. Despite this, examination of the large scale structure in superluminal radio sources strongly suggests that large scale symmetrical structure with two large radio lobes placed on either side of the compact emission is a common

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... menon among these objects. When a comparison is done between the large scale structure typically seen in double quasars and that seen in superluminal sources, it is found that the de-projected physical sizes estimated for superluminal quasars are similar to the size scales observed in the double quasars. Large scale radio structure is probably as common among apparent superluminal sources as it is in radio quasars.