A Study of 13 Powerful Classical Double Radio Galaxies (original) (raw)

2008, The Astrophysical Journal Supplement Series

We have carried out an extensive study of a sample of 13 large, powerful Fanaroff-Riley type II radio galaxies with the Very Large Array in multiple configurations 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 the whole the 13 FRII sources have symmetric structures with arm-length ratios close to unity, small misalignment angles and low values of radio core prominence, suggesting that these radio galaxies lie close to the plane of the sky. We have revisited some well known radio galaxy correlations using a large combined dataset comprising our radio galaxies and others from the literature. We confirm that the hotspot size correlates with the core-hotspot distance. The hotspot spectral index is correlated with, and flatter than the lobe spectral index, consistent with the assumptions of spectral aging models. Both the hotspot and lobe spectral index are correlated with redshift. The depolarization asymmetry in the lobes is not correlated with the radio core prominence or misalignment angle, which are statistical indicators of orientation. The 'Liu-Pooley' correlation of lobe depolarization with the lobe spectral index is significant in our radio galaxy To this end, we observed 13 FRII radio galaxies with the Very Large Array (VLA) in multiple configurations at 330 MHz, 1.4 GHz, 5 GHz, and 8 GHz. Here we present images of the total and polarized radio intensity, spectral index between 1.4 and 5 GHz, 0.3 and 1.4 GHz, and rotation measure between 1.4 and 5 GHz 1 . Further, we probe the relationship between different global characteristics of the radio galaxies by augmenting our data with additional galaxy data gleaned from the literature. We will subsequently refer to this extended, eclectic sample as the "combined" dataset, while the 13 FRII galaxies will be referred to as such.