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We analyze Chandra observations of diffuse soft X-ray emission associated with a complete sample of 3CR radio galaxies at z < 0.3. In this paper we focus on the properties of the spectroscopic sub-classes of high excitation galaxies (HEGs) and broad line objects (BLOs). Among the 33 HEGs we detect extended (or possibly extended) emission in about 40% of the sources; the fraction is even higher (8/10) restricting the analysis to the objects with exposure times larger than 10 ks. In the 18 BLOs, extended emission is seen only in 2 objects; this lower detection rate can be ascribed to the presence of their bright X-ray nuclei that easily outshine any genuine diffuse emission. A very close correspondence between the soft X-ray and optical line morphology emerges. We also find that the ratio between [O III] and extended soft X-ray luminosity is confined within a factor of 2 around a median value of 5. Both results are similar to what is seen in Seyfert galaxies. We discuss different processes that could explain the soft X-ray emission and conclude that the photoionization of extended gas, coincident with the narrow line region, is the favored mechanism.
115 - E. Torresi 2009
All the observations available in the Chandra and XMM-Newton archives have been used to investigate the X-ray spectral properties of 3C 33. In this paper is presented a complete X-ray analysis of the nuclear emission of this narrow line radio galaxy. The broad band spectrum of 3C 33 is complex. The hard part resembles that of Seyfert 2 galaxies, with a heavily obscured nuclear continuum (N_H~10^23 cm^-2) and a prominent Fe Kalpha line. This represents the nuclear radiation directly observed in transmission through a cold circumnuclear gas. On the other hand an unabsorbed continuum plus emission lines seem to fit well the soft part of the spectrum (0.5-2 keV) suggesting that the jet does not significantly contribute 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, strengthened by optical spectroscopy favor the photoionization scenario.
A spatially resolved analysis of the lobes of the radio galaxy Pictor A has been performed for the first time starting from a 50 ksec XMM-Newton observation. Magnetic field, B_{IC}, particle density, particle to magnetic field energy density ratios h ave been measured. Our study shows that B_{IC} varies through the lobes. On the contrary, a rather uniform distribution of the particles is observed. In both the lobes, the equipartition magnetic field, B_{eq}, is bigger than the Inverse Compton value, B_{IC}, calculated from the radio to X-ray flux ratio.
96 - P. Grandi 2007
We present an observation of XMM-Newton that unambiguously reveals the ``Seyfert 2 nature of the Broad Line Radio Galaxy 3C 445. For the first time the soft excess of this source has been resolved. It consists of unobscured scattered continuum flux a nd emission lines, likely produced in a warm photoionized gas near the pole of an obscuring torus. The presence of circumnuclear (likely stratified) matter is supported by the complex obscuration of the nuclear region. Seventy percent of the nuclear radiation (first component) is indeed obscured by a column density ~4*10^{23} cm^{-2}, and 30 % (second component) is filtered by ~7* 10^{22} cm^{-2}. The first component is nuclear radiation directly observed by transmission through the thicker regions. The second one is of more uncertain nature. If the observer has a deep view into the nucleus but near the edge of the torus, it could be light scattered by the inner wall of the torus and/or by photoionized gas within the Broad Line Region observed through the thinner rim of the circumnuclear matter.
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