1. 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)

2. Ubiquitous Variability of N H in Seyfert Galaxies N H variable in 23/25 sources Timescales from months to years Clumpy absorber Sub-parsec distance Leicester - Jan 04, 2009 Risaliti, Elvis & Nicastro 2002

3. Ubiquitous Variability of N H 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

4. Method: XMM long look of Mrk 766

5.  No absorption, “standard” model  N H ~10 23 cm -2, C.F. ~ 80% No continuum spectral variation

6. Ubiquitous Variability of N H in Seyfert Galaxies Eclipses on short time scales are common ! (~10 sources with confirmed occultations in hours-days) (Risaliti et al. 2010)

7.  N H ~2*10 23 cm -2  hours  N H ~10 23 cm -2  days  N H ~3*10 23 cm -2  days  N H ~10 23 cm -2  hours NGC 4388NGC 4151 UGC 4203NGC 7582 (Bianchi et al. 2009) Finding more sources with eclipses in ~hours-days

8. Eclipses of the X-ray source are COMMON in nearby AGN        cm  General results: V > 10 3 km/s D ~ 10 13 cm n ~ 10 10 -10 11 cm -2

9. HR NHNH CF Maiolino et al. 2010 Structure of the absorber NGC 1365 Suzaku

10. Tomography of the X-ray source A Relativistic Iron Line in NGC 1365 (Risaliti et al. 2009) Assumptions: 1)It is really a relativistic line 2)Long look (>300 ks) 3)Source in Compton-thin state 4)Complete 10-hours C-thick eclipse during obs.

11. Simulation: IXO observation of the eclipsing iron line IXO

12. Simulation: XMM observation of the eclipsing iron line

13. blue red IXO observation of the already observed eclipses

14. CONCLUSIONS Variability on short time scales is common in local AGNs  X-ray absorber == BLR clouds  Size of the X-ray source ~ a few R G Detailed analysis of the highest S/N X-ray eclipses:  “Cometary” shape of clouds Possible tests of GR effects & disk tomography