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The nature of the absorbing torus in compact Radio Galaxies

G. Risaliti·L. Woltjer·M. Salvati
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Abstract

We present BeppoSAX observations of the two radio galaxies PKS 1934-63 and S5 1946+708. Strong Iron Kalpha lines are detected in both objects indicating that the two sources are absorbed by column densities higher than 10^24 cm^(-2). Combining radio continuum, HI absorption and X-ray data we can constrain the physical state and the dimensions of the absorber. We find that the putative obscuring torus is molecular and located at a distance higher than 20 pc from the center in S5 1946+70. In PKS 1934-63 no radio nucleus has been observed. If this is due to free-free absorption a radius of only a few pc is inferred. Since the Kalpha lines have been detected only at 90% confidence, we also discuss the implications if they would be not as strong as found from our data. From our results it appears that the combination of hard X-ray data and spatially resolved HI absorption measurements provides a powerful diagnostic for conditions in the absorbing ``torus''.

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G. Risaliti, L. Woltjer, M. Salvati. 2003-01-27. The nature of the absorbing torus in compact Radio Galaxies. https://doi.org/10.1051/0004-6361%3A20030124

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