Accretion flows onto black holes Chris Done University of Durham

Spectral states Dramatic changes in continuum – single object, different days Underlying pattern in all systems High L/LEdd: soft spectrum, peaks at kTmax often disc-like, plus tail Lower L/LEdd: hard spectrum, peaks at high energies, not like a disc (McClintock & Remillard 2006) very high disk dominated high/soft Gierlinski & Done 2003

Moving disc – moving QPO Low frequency QPO – very strong feature at softest low/hard and intermediate and very high states (disc+tail) Moves in frequency: correlated with spectrum Moving inner disc makes sense of this. Disc closer in, higher f QPO. More soft photons from disc so softer spectra (di Matteo et al 1999) DGK07

Reflection from a slab eout qio ein eout ~ ein 1 + ein (1- cosqio) Reflection: wherever X-rays illuminate optically thick material. Competition between electron scattering and photoelectric absorption Low E – lots of photo-electric absorption by K shell of C,N,O so little reflection Higher E – lower abundance of higher Z elements. Less absorption so more reflection High E: Compton downscattering e.g. Fabian et al 2000 eout qio ein eout ~ ein 1 + ein (1- cosqio)

Reflection from a slab: pexriv XSPEC: pexrav Low E: reflection probability set by relative importance of scattering and photoelectric abs. High E: Compton downscattering so depends on spectral shape above bandpass Magdziarz & Zdziarski 1995 Makes peak 20-50 keV Photoelectric absorption edges Log s Electron scattering Incident spectrum Reflected spectrum

Relativistic effects Relativistic effects (special and general) affect all emission (Cunningham 1975) Hard to easily spot on continuum components Fe Ka line from irradiated disc – broad and skewed! (Fabian et al 1989) Broadening gives an independent measure of Rin – so spin if ISO (Laor 1991) Models predict increasing amount of reflection/line AND increasing width as go from low/hard to high/soft states flux Another area where Astro e2 will give major progress in an independent test of the accretion flow models. The accretion disc moves fast in a strong gravitational field, so both special and general relativistic effects modify its spectrum. Doppler shifts and length contraction mean that the emission from the disc moving towards us is blueshifted and boosted, while that moving away is redshifted and suppressed. Then time dilation and gravitational redshift drag everything redwards. The strength of these all effects decrease with radius. All emission from the disc is affected, but its much easier to see on intrinsically narrow features – lines. X-ray illumination of the disc gives iron Kalpha line. Moving inner disc models predict broader line in softer spectra. But the measured line profile can be distorted by narrow absorption features superimposed on the emission. The high spectral resolution of Astro e2 will unambiguously show these, enabling the intrinsic line profile to be measured. Energy (keV) Fabian et al. 1989

Gilfanov, Churazov & Revnivtsev 2000 Reflected spectra (1) Predicts increasing solid angle of disk as go from hard to soft Cyg X-1 fit to power law Gilfanov, Churazov & Revnivtsev 2000

Gilfanov, Churazov & Revnivtsev 2000 Reflected spectra (2) Many objects SAME G-W/2p correlation and CORRELATED increase in relativistic effects Zdziarski et al., 1999, Gilfanov et al 1999, Zycki et al 1999, Lubinski & Zdziarski 2001, Revnivtsev et al 2001 But seems more complex in high resolution data…. Gilfanov, Churazov & Revnivtsev 2000

Inhomogeneous spectra ? Overlap softer (and more reflection) Inner region harder (and less reflection) WE SEE THIS!! The disc models assumed that the emission thermalised. That’s not necessarily true at low L/Ledd where the flow is not very dense. If its not thermalising then its not cooling as efficiently so the flow heats up. This can lead to a hot, optically thin, geometrically thick inner flow replacing the inner disc. The hot electrons in this flow can compton upscatter any low energy photons from a residual outer disc, but there are not many of these, so the spectrum is hard Log n f(n) Log n

Makishima, Torii, Takahashi…..

Scale up to AGN AGN – much more massive so disc in UV

Spectral states Dramatic changes in continuum – single object, different days Underlying pattern in all systems High L/LEdd: soft spectrum, peaks at kTmax often disc-like, plus tail Lower L/LEdd: hard spectrum, peaks at high energies, not like a disc (McClintock & Remillard 2006) very high high/soft Gierlinski & Done 2003

‘Spectral states in AGN’ Disc BELOW X-ray bandpass. Only see tail 0.01 0.1 1 10 100 Intrinsic differences in spectrum (same M, different L/LEdd)

AGN spectral states Stretched out by lower disc temperature so not so obvious as in BHB BUT range in Lx/Lbol High mass accretion rates (high L/LEdd) have lower Lx/Lbol as dominated by UV disc Lower mass accretion rates (low L/LEdd) dominated by hard X-rays from hot flow

UV disc seen in Quasars! Bright, blue/UV continuum from accretion disc. Gas close to nucleus irradiated and photo-ionised – lines! Broad permitted lines ~ 5000 km/s (BLR) Narrow forbidden lines ~ 200 km/s (NLR) Forbidden lines suppressed if collisions so NLR is less dense than BLR Scaling these models up to the supermassive black holes in quasars, the only change should be that the disc emission is in the UV rather than X-ray region. The problem is knowing how far to scale them for an individual qso, knowing the BH mass. This has only recently become possible with the discovery of the relationships between the BH mass and the properties of the galaxy as a whole. Big BH live in big galaxies, little BH live in small ones. Also, only recently that enough high s/n data has become available to test these models – xmm-newton database Francis et al 1991

AGN/QSO Zoo!!! Optical

Scale up to AGN Wider range in mass and spin – all BHB born in similar way but AGN built by accretion Fuelling mechanism change: BHB companion star maximum mass accretion rate set by size of binary 10-6 < L/LEdd<0.5 Only very few have higher L/LEdd (GRS1915+105) Different fuelling of AGN means not limited in same way – can reach L/LEdd ≥ 1?

Mass of AGN?? Magorrian-Gebhardt relation gives BH mass!! Big black holes live in host galaxies with big bulges! Either measured by bulge luminosity or bulge mass (stellar velocity dispersion) or BLR 109 Black hole mass Scaling these models up to the supermassive black holes in quasars, the only change should be that the disc emission is in the UV rather than X-ray region. The problem is knowing how far to scale them for an individual qso, knowing the BH mass. This has only recently become possible with the discovery of the relationships between the BH mass and the properties of the galaxy as a whole. Big BH live in big galaxies, little BH live in small ones. Also, only recently that enough high s/n data has become available to test these models – xmm-newton database 103 Stellar system mass 106 1012

AGN spectral states High mass accretion rates (high L/LEdd) have lower Lx/Lbol ie higher Lbol/Lx! Vasuvaden & Fabian 2008

Seyfert 1 – Seyfert 2 Intrinsically same except for obscuration ? But differences in HIGH energy spectra (20-200 keV). S1’s softer than S2’s – but also have higher <L/LEdd> than S2 sample so same correlation as in BHB - softer when higher L/LEdd in LHS (Middleton, Done & Schurch 2008; Winter et al 2009)

Seyfert 1 - Quasars Similar spectra and line ratios, strong UV flux to excite lines, probably similar L/LEdd ~ 0.1-0.3 Increasing L Increasing M

Hot inner flow, no UV bright disc LINERS-S1-NLS1 Similar mass. Different L/LEdd Different ionisation NLS1 Increasing L/LEdd S1 disc Hot inner flow, no UV bright disc LINER Jester 2005; Leighy 2005; kording et al 2007

And the radio jet… link to spin? No special mQSO class – they ALL produce jets, consistent with same radio/X ray evolution Jet links to spectral state – hard state has steady radio jet which gets brighter as the hard X-rays get brighter Then collapses as make transition to disc (Fender et al 2005) 0.01Ledd L(radio) jet Scaling these models up to the supermassive black holes in quasars, the only change should be that the disc emission is in the UV rather than X-ray region. The problem is knowing how far to scale them for an individual qso, knowing the BH mass. This has only recently become possible with the discovery of the relationships between the BH mass and the properties of the galaxy as a whole. Big BH live in big galaxies, little BH live in small ones. Also, only recently that enough high s/n data has become available to test these models – xmm-newton database L(X-ray) accretion flow Gallo et al 2003

Hot inner flow, no UV bright disc LINERS-S1-NLS1 Similar mass. Different L/LEdd Different ionisation NLS1 ???? Increasing L/LEdd S1 disc Radio quiet Hot inner flow, no UV bright disc LINER Radio loudness Jester 2005; Leighy 2005; Kording et al 2007

Is this all? Is this really enough to explain range in behaviour of radio jets? Orientation with respect to jet Strong relativistic beaming FRI – BL Lacs – intrinsically weak lines (ie weak UV) FRII – Flat spectrum radio QSO – strong lines (strong UV disc)

Is this all? FRI – BL Lacs - fluffy FRII – Flat spectrum radio QSO

Is this all? Ghisellini et al 2010

weak disk, low excitation broader, slower jet, FRI L/Ledd~1 Disc+tail L/Ledd < 0.01 ADAF, weak disk, low excitation broader, slower jet, FRI L/Ledd~1 Disc+tail strong disk, high excitation Narrower, faster jet, FRII Log n Log n f(n) The disc models assumed that the emission thermalised. That’s not necessarily true at low L/Ledd where the flow is not very dense. If its not thermalising then its not cooling as efficiently so the flow heats up. This can lead to a hot, optically thin, geometrically thick inner flow replacing the inner disc. The hot electrons in this flow can compton upscatter any low energy photons from a residual outer disc, but there are not many of these, so the spectrum is hard Log n f(n) Log n

GRS 1915+105 Hard to get BHB at LEdd as in BINARY. Disc truncated by star so finite reservoir to build up in quiescence… but BIG binary can! GRS1915+105 orbital period is 33 days (cf < few days in other BHB). UNIQUE limit cycle variability in 50% of data - most likely because it goes to uniquely high L (Done Wardzinski & Gierlinski 2004) Belloni et al 2000

GRS 1915+105 Mirabel et al 1998

weak disk, low excitation broader, slower jet, FRI L/Ledd~1 Disc+tail L/Ledd < 0.01 ADAF, weak disk, low excitation broader, slower jet, FRI L/Ledd~1 Disc+tail strong disk, high excitation Narrower, faster jet, FRII Log n Log n f(n) The disc models assumed that the emission thermalised. That’s not necessarily true at low L/Ledd where the flow is not very dense. If its not thermalising then its not cooling as efficiently so the flow heats up. This can lead to a hot, optically thin, geometrically thick inner flow replacing the inner disc. The hot electrons in this flow can compton upscatter any low energy photons from a residual outer disc, but there are not many of these, so the spectrum is hard Log n f(n) Log n

Conclusions BHB – all pretty much 10 solar masses. Good evidence for last stable orbit at high luminosity. Transition to much harder spectra at lower luminosity. Can be explained by progressive evaporation of inner disc into a hot flow (which is also the base of the jet) SAME model can also make sense of the variability, both the low frequency QPO and the broad band noise So seems like a pretty good model. So apply to AGN – seems to scale pretty well with mass Mass has much bigger spread (105-9 Msun) More complex environment – torus/dust obscuration – inclination! Spectrum and jet change with L/LEdd but jet may depend on spin as well. Feedback from this controls galaxy formation Fabulous time, both in terms of data available and for me personally. For the first time there is enough data

Observed disc spectra kTe =50 keV Low/moderate spin as predicted by SN collapse LMXBs (Gammie et al 2004; a < 0.8) Some controversy over GRS1915+105 (Middleton et al 2006; McClintock et al 2006) Depends on model of Compton (Torok) We need slim disc models as well!! Straub Middleton, Davis, Done & Gierlinski 2005

Observed disc spectra kTe free Low/moderate spin as predicted by SN collapse LMXBs (Gammie et al 2004; a < 0.8) Some controversy over GRS1915+105 (Middleton et al 2006; McClintock et al 2006) Depends on model of Compton (Torok) We need slim disc models as well!! Straub Middleton, Davis, Done & Gierlinski 2005