1999ApJ...511...84H

We present deep 8.4 GHz VLBI images of the faint nuclei in seven lobe-dominated quasars (LDQs): 3C 175, 3C 204, 3C 205, 3C 215, 3C 351, 0821+447, and 0839+616 . These images, made from data obtained in 1988 and 1991 with high-sensitivity VLBI arrays, have a typical rms noise level of ∼0.03 mJy per beam and resolution of ∼0.5 mas. The parsec-scale jet structures are generally greater in extent and complexity than those seen on many previous, less sensitive maps of other LDQ nuclei; the jet in 3C 204 bends through at least 10°, and the jet in 3C 205 extends out to ∼5 mas. Observations of 3C 204, 3C 205, and 0839+616 at two epochs reveal clear flux density variability in 3C 204 and 3C 205, but none of these sources shows any evidence for outward motion of jet components; their mean apparent transverse velocity is -0.47±0.43h^–1c, from which we determine a 3 σ upper limit on their mean expansion speed of ∼0.8 h^–1c (H₀=100h km.s^–1.Mpc^–1, q₀=0.5). The innermost jet knot in 3C 204 underwent a marginal position angle swing away from the mean jet axis. We also present the first 8.4 GHz A-array VLA images for all the objects except 3C 351. All the sources except 0821+447 display one-sided VLBI and VLA jets, which lie on the same side of the VLBI core and are generally well aligned (to within ∼5°). In addition, we analyze the statistics of projected linear size, relative nuclear strength, and misalignment angle for the 3CR and Jodrell Bank LDQ samples. We conclude that our results are generally consistent with a fairly simple relativistic jet model and with the unification of core-dominated quasars, lobe-dominated quasars, and possibly even powerful radio galaxies; there is a marginal suggestion that the quasars in our samples have a restricted range of angles to the line of sight (e.g., 0° to ∼45°).