Extreme Superluminal Motion in the Curved Jet of PKS 1502+106

Abstract

In this paper we present a multifrequency and multiepoch study of \object{PKS 1502+106} at radio frequencies. The analysis is based on an EVN (European VLBI Network) dataset at 5 GHz and archive VLBA (Very Long Baseline Array) datasets at 2.3, 8.3, 24.4 and 43.1 GHz over a period of 8 years. The source is characterized by a multi--component one--sided jet at all epochs. The high--resolution images at 5, 8.3, 24.4 and 43.1 GHz show a curved jet morphology in the source. The radio core brightness temperature approaches the equipartition limit. Superluminal motions of $37.3\pm9.3 c$, $22.0\pm15.5 c$, $10.5\pm2.6 c$ and $27.9\pm7.0 c$ are measured in four distinct components of the jet. Our analysis supports the idea that the relativistic jet in \object{PKS 1502+106} is characterised by extreme beaming and that its radio properties are similar to those of $\gamma$--ray loud sources.