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