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One more surprise from the Circinus Galaxy: BeppoSAX discovery of a transmission component in hard X-rays

G. Matt·M. Guainazzi·R. Maiolino·S. Molendi·G. C. Perola·L. A. Antonelli·L. Bassani·W. N. Brandt·A. C. Fabian·F. Fiore·K. Iwasawa·G. Malaguti·A. Marconi·J. Poutanen
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Abstract

The Circinus Galaxy has been observed, for the first time above 10 keV, by BeppoSAX. An excess emission above the extrapolation of the best fit 0.1--10 keV spectrum is apparent in the PDS data. The most likely explanation is that we are observing the nucleus through a column density of about 4x10**24 cm-2, i.e. large enough to completely block the radiation below 10 keV but small enough to permit partial transmission above this energy.

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G. Matt, M. Guainazzi, R. Maiolino, S. Molendi, G. C. Perola, L. A. Antonelli, L. Bassani, W. N. Brandt, A. C. Fabian, F. Fiore, K. Iwasawa, G. Malaguti, A. Marconi, J. Poutanen. 1998-11-19. One more surprise from the Circinus Galaxy: BeppoSAX discovery of a transmission component in hard X-rays. https://arxiv.org/abs/astro-ph/9811301

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