We present an analysis of the extreme obscuration variability observed during an XMM-Newton 5-d continuous monitoring of the active galactic nuclei (AGN) in NGC 1365. The source was in a reflection-dominated state in the first ~ 1.5 d, then a strong increase in the 7-10 keV emission was observed in ~10 h, 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 Ds < 1013 cm, a distance of the obscuring clouds R ~ 1016 cm and a density n ~ 1011 cm-3. These values suggest that the X-ray absorption/reflection originates from the broad-line region clouds. This is also supported by the resolved width of the iron narrow Kα emission line, consistent with the width of the broad Hβ line. © 2008 The Authors. Journal compilation © 2008 RAS.
The XMM-Newton long look of NGC 1365: Uncovering of the obscured X-ray source / Risaliti G.; Salvati M.; Elvis M.; Fabbiano G.; Baldi A.; Bianchi S.; Braito V.; Guainazzi M.; Matt G.; Miniutti G.; Reeves J.; Soria R.; Zezas A.. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. LETTERS. - ISSN 1745-3933. - ELETTRONICO. - 393:(2009), pp. L1-L5. [10.1111/j.1745-3933.2008.00580.x]
The XMM-Newton long look of NGC 1365: Uncovering of the obscured X-ray source
Risaliti G.;
2009
Abstract
We present an analysis of the extreme obscuration variability observed during an XMM-Newton 5-d continuous monitoring of the active galactic nuclei (AGN) in NGC 1365. The source was in a reflection-dominated state in the first ~ 1.5 d, then a strong increase in the 7-10 keV emission was observed in ~10 h, 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 Ds < 1013 cm, a distance of the obscuring clouds R ~ 1016 cm and a density n ~ 1011 cm-3. These values suggest that the X-ray absorption/reflection originates from the broad-line region clouds. This is also supported by the resolved width of the iron narrow Kα emission line, consistent with the width of the broad Hβ line. © 2008 The Authors. Journal compilation © 2008 RAS.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
