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Monthly Notices of the Royal Astronomical Society: Letters 393 (2009) L1-L5
The XMM-Newton long look of NGC 1365: uncovering of the obscured X-ray source
G. Risaliti, M. Salvati, M. Elvis, G. Fabbiano, A. Baldi, S. Bianchi1, V. Braito, M. Guainazzi, G. Matt1, G. Miniutti2, J. Reeves3, R. Soria, A. Zezas

We present an analysis of the extreme obscuration variability observed during an XMM-Newton 5-days continuous monitoring of the AGN in NGC 1365. The source was in a reflection-dominated state in the first ~1.5 days, then a strong increase of the 7-10 keV emission was observed in ~10 hours, followed by a symmetric decrease. The spectral analysis of the different states clearly shows that this variation is due to an uncovering of the X-ray source. From this observation we estimate a size of the X-ray source D_S<10^13 cm, a distance of the obscuring clouds R~10^16 cm and a density n~10^11 cm^{-3}. These values suggest that the X-ray absorption/reflection originate from the broad line region clouds. This is also supported by the resolved width of the iron narrow Kalpha emission line, consistent with the width of the broad Hbeta line.
1 :  Dipartimento di Fisica, Universita degli Studi Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
2 :  APC - UMR 7164 - AstroParticule et Cosmologie
3 :  Astronomy Group, School of Geographical and Physical Sciences, University of Keele, Keele, Staffordshire, ST5 5BG, UK.
Physique/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique
galaxies: individual: NGC 1365
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