New results on the importance of absorption in AGN

Transcription

1 New results on the importance of absorption in AGN Jane Turner Collaborators: Lance Miller (Oxford) James Reeves, Andrew Lobban (Keele) Steve Kraemer (CUA)

2 Multiple Layers of Ionized Gas common NGC 3516 Turner et al XMM,Turner et al Multiple, variable layers of ionized gas observed in many sources, when we look hard enough

3 High N H /ξ components isolated HEG NGC 3516 Neutral Fe Kα Fe XXV Fe XXVI Abs n lines Fe XXV, XXVI V ~ 1000 km/s outflow N H > 5x10 23 cm -2 log ξ ~4.3 Oct 2006 Nov 2001 Observed energies rules out local (z=0) origin

4 Covering Changes Spectral & most of flux variability - changes in covering of log ξ ~2 layer, 40%-60% in N H ~10 23 cm -2 Turner et al 2008 Markowitz et al 2008 Covering variation also explains much of flux variability (cf NGC 4151 Puccetti et al 2007) Risaliti et al 2009a,2009b found evidence for obscuration & de-obscuration by absorbing cloud system in NGC 1365

5 Partial Covering Back to an old idea, e.g. Holt 1980, Reichert 1985, Matsuoka et al 1990, Piro et al 1990, 1992 Likely scenario - X-ray absorber exists close-in as part of a clumpy (equatorial?) disk wind containing structures on many size scales -Sim et al 2007

6 Occultation events in MCG & NGC 3516 McKernan & Yaqoob 1998 Occultation by optically-thick cloud explains flux and spectral variability in target low state, including Fe emission line Deep dips - eclipse type events?

7 Flat Bottomed Dips MCG McKernan & NGC 3516 Turner et al 08- dip shape - Yaqoob 98 - dip shape from inhomogeneities in emitter or absorber inhomogeneities in emitter d cloud ~ 3 x v 4 cm ~ R s Dip shape hard to explain in light-bending model? Effective spatial resolution ~million x greater than possible w/ current X-ray

8 Compton-thick absorbers in type 1 AGN New evidence from Suzaku that partial-covering by Compton-thick gas is important

9 Compton-thick Absorber in Type 1 QSO, 1H Absn models used for XMM data-e.g. Pounds et al, Page et al Without PC absorption (Turner et al. 2009) With PC absorption Strong hard excess Cannot be fit by reflection N H >10 24 cm -2 covering >70% of emitter L bol ~10 47 erg/s Located. within BLR Disk wind?

10 Suzaku PIN Results Flux above 10 kev generally stronger than expected from reflection models MCG R ~ 2-5 Ballantyne et al 03, Miniutti et al 07 NGC 4051 R ~ 7 Terashima et al 2008 Mrk 335 R ~ 3 Larsson et al H & PDS fits require PC absorption

11 Covering Fractions also c.f. variable covering by large columns in Mrk % (Miller et al 07, Turner et al 07) NGC % (Turner PDS et al 08) MCG % (Miller et al 08) also 1H (Longinotti et al 09) BUT fitted covering fractions may be misleading as Compton scattering not accounted for

12 Fe line strength from absorber Observed neutral Fe line does not rule out these models -May not be from distant reprocessor (e.g. Yaqoob & Murphy 2009) while the PC-absorber, being ionized, may produce very little observable Fe K line

13 NGC 4051 Suzaku Observations: 2005 Nov 10, 2008 Nov 6 & 23 HETG observations: 2008 Nov 6

14 Variable componentnote hard excess Intrinsically-variable continuum plus apparent variability from changing absorption? Offset component

15 black = low Variable component red=high Offset component Lines at 5.4, 5.9 kev in all three XIS detectors, present at 99.9% confidence Do not track continuum, flux consistent w/ constant Disk-line horns or Cr enhancement from spallation

16 𐅃 ~ Nov Nov23 Uncovered 20% 40% 35% 9 x cm -2 logξ~2.1 80% 12% 16% 4 x10 24 cm -2 logξ~2.6 0% 48% 49% Full layer 2x10 22 logξ ~~ 3.3 vel ~4600 km/s outflow

17 Summary Variable covering absorber can explain spectral shape & much of observed flux variability in the best-studied Seyferts NGC 3516/MCG light curves show dip events - favor absorption models - provide way to map AGN inner regions ahead of optics development A number of AGN have strong flux above 10 kev, further favoring absorption models Physical explanation - disk winds - developing models look promising Astro-H/IXO needed to separate features and determine the details of the accreting/outflowing gas