SIMBAD references

1999ApJ...511...84H - Astrophys. J., 511, 84-104 (1999/January-3)

Deep 8.4 GHz VLBI images of seven faint nuclei in lobe-dominated quasars.

HOUGH D.H., ZENSUS J.A., VERMEULEN R.C., READHEAD A.C.S., PORCAS R.W., RIUS A., RECTOR T.A., LENZ G.C., DAVIS M.A. and SNOWDALL J.C.

Abstract (from CDS):

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°).

Abstract Copyright:

Journal keyword(s): Galaxies: Jets - Galaxies: Structure - Galaxies: Quasars: General - Radio Continuum: Galaxies - Techniques: Interferometric

Nomenclature: Table 2: [HZV99] 3C NNN C, [HZV99] 3C NNN JN, [HZV99] HHMM+DDd C, [HZV99] HHMM+DDd JN, N=18.

Simbad objects: 20

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:1999ApJ...511...84H and select 'bookmark this link' or equivalent in the popup menu