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The hard X-ray properties of the Seyfert nucleus in NGC 1365

G. Risaliti·R. Maiolino·L. Bassani
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Abstract

We present BeppoSAX observations of the Seyfert 1.8 galaxy NGC1365 in the 0.1--100 keV range. The source was 6 times brighter than during an ASCA observation 3 years earlier. The 4--10 keV flux is highly variable during the BeppoSAX observation, while the soft (0.1-4 keV) emission is constant within the errors. Both a cold and a warm reflector and a cold absorber are required to explain the observed spectrum. The comparison between ASCA and BeppoSAX spectra strongly suggests that the circumnuclear material has a more complex structure than a simple homogeneous torus, with quite different absorbing gas columns along different lines of sight. A broad iron K_alpha line is also present in the spectrum, with the peak energy significantly redshifted. This can be explained by means of a relativistic disk line model. Alternatively, a warm absorption Fe line system with N_H ~ 10^23 cm^(-2) could account for the observed line profile.

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G. Risaliti, R. Maiolino, L. Bassani. 2000-02-08. The hard X-ray properties of the Seyfert nucleus in NGC 1365. https://arxiv.org/abs/astro-ph/0002169

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