43 GHz-VLBI observations of 3C273 after a flux density outburst in 1988

Abstract

A total of 43 GHz images of the bright quasar 3C273 at epochs 1988.48 and 1989.19, obtained from VLBI observations made shortly after a large flux density outburst in the optical/IR band in March 1988 are presented. The later observations reveal a more complex core-jet structure than the earlier ones, indicating superluminal expansion with apparent speed of 5.5 + or - 0.8. The ejecta appear at position angles relative to the core different from those of older components, seen at larger distances, suggesting motion along curved trajectories. These data, combined with those from the literature, suggest a quasi-sinusoidally curved ridgeline of the jet near the core.