2005/11/29 by Paola Grandi, P. Grandi, Giuseppe Malaguti +4
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/500100
published as Astrophys.J.642:113-125,2006 · ApJ accepted, 33 pages, 6 figures
arxiv created 2005/11/29 · openalex publication_date 2006/04/28 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/31
A systematic analysis of a large sample of radio-loud active galactic nuclei (AGNs) available in the BeppoSAX public archive has been performed. The sample includes 3 narrow-line radio galaxies (NLRGs), 10 broad-line radio galaxies (BLRGs), 6 steep-spectrum radio quasars (SSRQs), and 16 flat-spectrum radio quasars (FSRQs). According to the unified models, these classes correspond to objects with increasing viewing angles. As expected, the presence of a nonthermal beamed component emerges clearly in FSRQs. This class shows in fact a featureless continuum (with the exception of 3C 273) and a significantly flatter average spectral slope. However, traces of a nonthermal Doppler-enhanced radiation are elusive in the other classes. We find that the iron line equivalent widths (EWs) are generally weaker in radio-loud AGNs than in Seyfert 1 galaxies, and we confirm the presence of an X-ray Baldwin effect; that is, a decrease of EW with the 2-10 keV luminosity from Seyfert galaxies to BLRGs and quasars. Since the EW- L 2-10 keV anticorrelation is present also in radio-quiet AGNs alone, this effect cannot be ascribed entirely to a strongly beamed jet component. Possible alternative interpretations are explored.