A study of 13 powerful classical double radio galaxies

P. Kharb, C. P. O'Dea, S. A. Baum, R. A. Daly, M. P. Mory, M. Donahue, E. J. Guerra

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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 and 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 FR II 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 data set comprising our radio galaxies and others from the literature. We confirm that the hot spot size correlates with the core-hot spot distance. The hot spot spectral index is correlated with and flatter than the lobe spectral index, consistent with the assumptions of spectral aging models. Both the hot spot 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 sample. Furthermore, the lobe with the steeper spectral index and greater depolarization is shorter and fatter. The arm-length ratio seems to be correlated with the misalignment angle between the two sides of the radio source and strongly anticorrelated with the axial ratio, consistent with environmental effects and/or a change in the outflow direction. In this sample, asymmetries in the local environments and/or motion of the outflow axis are likely to be more important than relativistic beaming effects.

Original languageEnglish (US)
Pages (from-to)74-110
Number of pages37
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Jan 2008

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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