VLBI OBSERVATIONS OF THE GAMMA-RAY BLAZAR-1611+343

As part of an effort to observe high-energy gamma-ray blazars with VLB I, we have produced 8 and 2 GHz VLBI images, at eight epochs, of the q uasar 1611+343, which has been detected by the EGRET telescope on boar d the Compton Gamma Ray Observatory. The VLBI data have been taken fro m the geodetic database of the Washington VLBI correlator. As is expec ted for a gamma-ray quasar, we find that 1611+343 possesses a jet with several compact components moving at apparent superluminal speeds. We have detected five components and have measured speeds for the outer four of 6.7 +/- 1.6, 3.8 +/- 1.4, 7.6 +/- 1.3, and 11.5 +/- 2.3 h(-1)c from the outermost component inward. (H-0 = 100 h km s(-1) Mpc(-1), q (0) = 0.5.) By comparing the apparent superluminal expansion speeds wi th a lower limit to the Doppler beaming factor derived from X-ray obse rvations, we have calculated an upper limit on the angle of the jet to the line of sight of theta less than or equal to 6.degrees 8 and a lo wer limit to the Lorentz factor of the components of Gamma greater tha n or equal to 7.1. We have mapped the two-dimensional projected struct ure of the VLBI jet and clearly see different trajectories for differe nt components at the same distance from the core, which rules out a co ntinuous jet model for this source. A possible connection is found bet ween enhanced levels of gamma-ray activity and the ejection of new VLB I components from the core.