The structure of AGNs from X-ray eclipses
Guido Risaliti (CfA & INAF-Arcetri)
M. Salvati, E. Nardini (INAF-Arcetri), R. Maiolino (INAF-Roma), G. Matt, S. Bianchi (Roma3), V. Braito (Leicester), M. Elvis, G. Fabbiano, (CfA)
Ubiquitous Variability of NH in Seyfert Galaxies
NH variable in 23/25sources
Timescales from months to years
Clumpy absorberSub-parsec distance
Leicester - Jan 04, 2009Risaliti, Elvis & Nicastro 2002
Ubiquitous Variability of NH in Seyfert Galaxies
Common also on short time scales!(~10 sources with confirmed occultations in hours-days)
- Method: * Detection of candidate occultations * Confirmation through spectral analysis
-Applications: * Physical parameters of the X-ray source and the X-ray absorber * Hints on the geometrical structure of the absorbing clouds * Shape of the absorbing clouds * POSSIBLE EXPERIMENT OF DISK TOMOGRAPHY
Method: XMM long look of Mrk 766
No absorption, “standard” model
NH~1023cm-2,C.F. ~ 80%No continuum spectral variation
Ubiquitous Variability of NH in Seyfert Galaxies
Eclipses on short time scales are common !(~10 sources with confirmed occultations in hours-days)
(Risaliti et al. 2010)
NH~2*1023 cm-2
hours
NH~1023 cm-2
days
NH~3*1023 cm-2
days
NH~1023 cm-2
hours
NGC 4388 NGC 4151
UGC 4203 NGC 7582
(Bianchi et al. 2009)
Finding more sources with eclipses in ~hours-days
Eclipses of the X-ray source are COMMON in nearby AGN
cm
General results:
V > 103 km/s
D ~ 1013 cm
n ~ 1010-1011 cm-2
HR
NH
CFMaiolino et al. 2010
Structure of the absorber
NGC 1365 Suzaku
Tomography of the X-ray sourceA Relativistic Iron Line in NGC 1365
(Risaliti et al. 2009)
Assumptions:
1) It is really a relativistic line2) Long look (>300 ks)3) Source in Compton-thin state4) Complete 10-hours C-thick eclipse during obs.
Simulation: IXO observation of the eclipsing iron line
IXO
Simulation: XMM observation of the eclipsing iron line
blue
blue
blue
blue
red
red
red
red
IXO observation of the already observed eclipses
CONCLUSIONS
• Variability on short time scales is common in local AGNs X-ray absorber == BLR clouds Size of the X-ray source ~ a few RG
• Detailed analysis of the highest S/N X-ray eclipses: “Cometary” shape of clouds
• Possible tests of GR effects & disk tomography
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