Distance-independent evidence for relativistic motion in the quasar NRAO 140

VLBI radio and X-ray observations were made of the bright X-ray quasar NRAO 140. The radio structure consists of two very compact components plus a more diffuse jet. Based on the standard synchrotron theory, the Compton X-ray emission from one of these compact components was found to exceed the observed value by three orders of magnitude. Since this result is independent of distance and there is no evidence for coherent emission, it is concluded that the component is moving toward us at a relativistic speed with a Lorentz factor exceeding 4. Future observations should reveal superluminal separation of the components, as well as help in determining which components are undergoing relativistic motion.