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D. H. Hough, N. Wing, J. P. Linick (Trinity U.), S. M. Escobedo (Trinity U. and San Antonio College)
We report on recent centimeter-wavelength VLBI observations of parsec-scale jets in the nuclei of lobe-dominated quasars (LDQs). Our complete sample of 25 LDQs is drawn from the revised 3CR survey. Space VLBI observations of 3C263 at 5 GHz show a transverse-resolved jet. Phase-referenced VLBA images of the very faint nuclei in 3C9, 3C14, 3C432, and 4C16.49 at 8.4 GHz all exhibit one-sided parsec-scale jets that are well-aligned with kiloparsec-scale jets. Multiple-epoch VLBI images of 3C207, 3C208, 3C212, 3C245, 3C249.1, and 3C263 reveal superluminal motion in all these objects; in some objects, the jet trajectory is clearly non-linear (perhaps helical?) and different jet components have different speeds. Spectral (5-8.4 GHz) VLBA images of 3C207, 3C212, 3C263, and 3C334 tend to show flat-spectrum cores and steep-spectrum jets. Polarization VLBA images of 3C207 and 3C275.1 suggest longitudinal magnetic field ordering in their jets; the fractional polarizations are approximately 10-20 %, with roughly 5 % upper limits in four additional sources (3C212, 3C263, 3C270.1, and 3C334). These results are generally consistent with relativistic jet models and active galaxy unification scenarios.
We gratefully acknowledge support from the AAS Small Research Grant Program and the NSF-RUI Program.