2009/01/21 by E. Torresi, P. Grandi, M. Guainazzi +3 · 22 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Ion #Ionization #Line (geometry) #Photoionization #Physics #Radio galaxy #Spectral line #Spectroscopy #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/200810944
published in Astronomy and Astrophysics 498(1), 61-66 (EDP Sciences) · 7 pages, 5 figures, accepted for publication in A&A
arxiv created 2009/01/21 · openalex publication_date 2009/03/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the X-ray spectral properties of 3C 33 by analyzing all the observations available in the <i>Chandra<i/> and <i>XMM-Newton<i/> archives. In this paper we present a complete X-ray analysis of the nuclear emission of this narrow-line radio galaxy. The broad-band spectrum of 3C 33 is complex. Its hard part resembles that of Seyfert 2 galaxies, which have a heavily obscured nuclear continuum (<i>N<i/><sub>H<sub/> ~ 10<sup>23<sup/> cm<sup>-2<sup/>) and a prominent Fe K<i>α<i/> line. This represents the nuclear radiation observed directly in transmission through a cold circumnuclear gas. On the other hand an unabsorbed continuum plus emission lines seem to reproduce the soft part of the spectrum (0.5-2 keV) well, suggesting that the jet does not contribute significantly to the X-ray emission. We discuss the possible collisional or photoionized origin of the gas that emits the soft X-ray lines. Our results, supported by those from optical spectroscopy, favor the photoionization scenario.