A Study of 13 Powerful Classical Double Radio Galaxies

We have carried out an extensive study of a sample of 13 large, powerfulFanaroff-Riley type II radio galaxies with the Very Large Array in multipleconfigurations at 330 MHz, 1.4, 5 and 8 GHz. We present the total intensity,polarization, spectral index, and rotation measure maps of the sources. On thewhole the 13 FRII sources have symmetric structures with arm-length ratiosclose to unity, small misalignment angles and low values of radio coreprominence, suggesting that these radio galaxies lie close to the plane of thesky. We have revisited some well known radio galaxy correlations using a largecombined dataset comprising our radio galaxies and others from the literature.We confirm that the hotspot size correlates with the core-hotspot distance. Thehotspot spectral index is correlated with, and flatter than the lobe spectralindex, consistent with the assumptions of spectral aging models. Both thehotspot and lobe spectral index are correlated with redshift. Thedepolarization asymmetry in the lobes is not correlated with the radio coreprominence or misalignment angle, which are statistical indicators oforientation. The `Liu-Pooley' correlation of lobe depolarization with the lobespectral index is significant in our radio galaxy sample. Further, the lobewith the steeper spectral index and greater depolarization is shorter andfatter. The arm-length ratio seems to be correlated with the misalignment anglebetween the two sides of the radio source and strongly anti-correlated with theaxial ratio, consistent with environmental effects and/or a change in theoutflow direction. In this sample, asymmetries in the local environments and/ormotion of the outflow axis are likely to be more important than relativisticbeaming effects.Comment: 91 pages, 69 figures, Accepted for publication in the ApJ Supp. Ser., Paper substantially revised after additional referee-reports, Conclusions remain largely unchange