Black holes: NeXT steps…. Chris Done University of Durham & ISAS

Appearance of BH should depend only on mass and spin (black holes have no hair!) Plus mass accretion rate – L/L Edd M  : Quasars (?) M  : ULX 3-20 M  : Galactic black holes How does accretion flow change as function of M/M  spin and L/L Edd ? Black holes

Big questions: First BH & galaxies stellar bulge (  or M B ) gives BH mass – link between galaxy and BH QSO peak at z~2 L/L Edd ~1 onto ~10 8 M 0 (local NLS1) First SMBH = first galaxies. QSOs z~6, so first BH ~10 6 M 0 z~10? Black hole mass Stellar system mass

Big questions:ULX Ultra - Luminous X-ray sources in spiral arms of nearby starforming galaxies – ULX L~ ergs s -1 M~ M  for L<L Edd Hard for stellar evolution to make BH > 50 M  How to form bigger BH? How to get L/L Edd >1? Need to know mass!!! Gao et al 2003

Nature of the jet=AGN feedback on cluster cooling! link to spin ? MRI simulations say powerful jets for moderate spin – don’t need a= (weak) jet a=0 LMXB: gravitational waves in core collapse may limit spin to <0.8 ( Gammie et al 2002 ) AGN: high spin for BH in major mergers (big galaxies) but not from multiple small mergers Radio loud/quiet? Need to measure spin!!! Big questions: BH jet – spin?

Big questions: strong gravity Accreting BH: huge X-ray luminosity close to event horizon Bright emission from region of strong spacetime curvature Spectral distortions depend on velocity, geometry and GR Observational constraints on strong gravity if we know velocity/geometry! Need to understand accretion!

Differential Keplerian rotation Viscosity B: gravity  heat Thermal emission: L = A  T 4 Temperature increases inwards GR last stable orbit gives minimum radius R ms a=0: T max = (M/M  ) -1/4 ( L/L Edd ) 1/4 1 keV (10 7 K) for 10 M  10 eV (10 5 K) for 10 8 M  a=0.998 T max ~ 2.2 T max (a=0) AGN: UV disc, ISM absorption, mass more uncertain. XRB… Spectra of accretion flow: disc Log Log f( 

Disc in X-ray band so not so heavily absorbed as UV Huge amounts of high s/n data Variability timescales ms – year (observable!) hours – 10 8 years in quasars Observational template of accretion flow as a function of L/L Edd onto ~10 M  BH Need ASM… Galactic Binary systems 7 years

Bewildering variety of spectra from single object in XRB! Underlying pattern High L/L Edd : soft spectrum, peaks at kT max often disc-like, plus tail Lower L/L Edd : hard spectrum, peaks at high energies, not disc! All GBH in RXTE archive consistent with SAME spectral evolution < L/L Edd < 1 How is hard X-ray tail produced? Why change with L/L Edd ? Done & Gierlinski 2003 X-ray Spectra

Observed GBH spectra RXTE archive of many GBH Same spectral evolution < L/L Edd < 1 Need this sort of data for AGN Done & Gierliński  )  3-6.4)  )

Disc models assumed thermal plasma – not true at low L/L Edd Instead: hot, optically thin, geometrically thick inner flow replacing the inner disc (Shapiro et al. 1976; Narayan & Yi 1995) Hot electrons Compton upscatter photons from outer cool disc Few seed photons, so spectrum is hard Accretion flows without discs Log Log f( 

Qualitative and quantitative models: geometry Log Log f(  Log Log f(  Hard (low L/L Edd ) Soft (high L/L Edd ) Done & Gierliński 2004

Moving disc – moving QPO Low frequency QPO – very strong feature at softest low/hard and intermediate and very high states Moves in frequency correlated with spectral slope Moving inner disc makes sense of this. Disc closer in, higher f QPO. But also more soft photons from disc so softer spectra (di Matteo Psaltis 1999)

Qualitative and quantitative models: geometry Log Log f(  Log Log f(  Hard (low L/L Edd ) Soft (high L/L Edd ) Done & Gierliński 2004

And jet…. ALL produce jet and are consistent with same radio/X ray evolution No special  QSO class Depends on spectrum - maximum radio at brightest low/hard, intermediate and very high states (like QPOs) i.e. L/L Edd (Merloni et al 2003; Falke et al 2004) Strongly quenched in disky spectra…. Gallo et al 2003

And link to jet behaviour! Sudden quenching of jet for disky spectra! Need geometrically thick flow to get large scale B field for jet? MRI gives jet from accretion flow – more powerful at higher spin but doesn’t require extreme a=0.998 (even present at a=0: Kataoka’s talk) Need to MEASURE spin Big questions: X-ray tail – jet? Fender Belloni & Gallo 2004

Observed disc spectra: spin? Pick ONLY disky ones L/L Edd  T 4 max (Ebisawa et al 1993; Kubota et al 1999; 2001) Proportionality gives R ms i.e. a Bit tricky as disc not blackbody. Some Compton distortion in upper layers of disc – f col Good models now (full vertical disc structure + radiative transfer with metals + full GR) Davis et al 2005 RANGE a = but NOT extreme (depend on i, M, D) Davis, Done Blaes 2006

Gierlinski & Done 2003 Observed disc spectra Pick ONLY disky ones L/L Edd  T 4 max (Ebisawa et al 1993; Kubota et al 1999; 2001) Proportionality gives R ms i.e. a Bit tricky as disc not blackbody. Some Compton distortion in upper layers of disc – f col Good models now (full vertical disc structure + radiative transfer with metals + full GR) Davis et al 2005 RANGE a = but NOT extreme (depend on i, M, D)

Relativistic effects Fabian et al Energy (keV) flux Relativistic effects (special and general) affect all emission (Cunningham 1975) Hard to easily spot on continuum components Fe K  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 width as go from low/hard to high/soft states

Problems: extreme Fe lines Broad iron lines are common in GBH. Some indications of increasing width with spectral softness But some are extremely broad, indicating high spin (if disc to ISO) and extreme emissivity – tapping spin energy of black hole? (Miller et al 2002; 2003; 2004; Minuitti et al 2004) Miller et al 2004 BUT these are the same objects for which a<~0.7 from disc spectra Mainly in VHS and softest low/hard states (intermediate states) flow extends below ISO? B field means not force free so LSO distorted…

XTE J : real conflict QPO and broadband data say that disc not down to ISO (RXTE) Done & Gierlinski < L/L Edd < 1

Extreme line in bright LH state of J1650 MECS data (moderate resolution from BeppoSAX) pexriv+narrow line. Best fit is extreme spin (Rin=2) and emissivity q=3.5 ( Miniutti et al 2004) But ionised reflection – line is intrinsically comptonised ( Ross, Fabian & Young 1999) Done & Gierlinski 2005

Ionisation balance in all these from Done et al 1992 and is VERY approximate! Slab temperature given rather than calculated! Constant density ionised disc (CDID/reflion) models of Ballantyne, Iwasawa & Fabian 2001; Ross & Fabian 2005 Irradiated slab so  and temperature drops as go deeper Also includes compton UPSCATTERING! SMEARS edge Ross, Fabian & Young 1999 Reflection from a slab: constant n pexriv:  =3x10 3 CDID:  =10 3

Extreme line in bright LH state of J1650 Proper reflection models: very different shape for ionised reflection – line and edge are intrinsically broadened by Comptonisation in the disc ( Ross, Fabian & Young 1999) Still extreme but relativistic effects only  2 =13 not 190 as for pexriv. Significance much reduced Done & Gierlinski 2005

Extreme line in bright LH state of J1650 Absorption lines – outflow. Rin~10 with normal emissivity. Nh~10 23, log  =2-3 Need strong dip at 7.5keV so either fast outflow at v~0.1c or else strong abs at 7.5 from K  and/or Ni K  Done & Gierlinski 2005

Absorbers now commonly seen GRS and J in ASCA data (Ueda et al 1998; Kotani et al 2000) XMM 3 disky spectra. BIG dips - 7.5keV! Also Suzaku x1630 Sala et al 2006, Kubota et al 2006 Chandra HETG Miller et al 2006 Chandra absorption lines – outflow of 1500 km/s, broadening by velocity dispersion of similar speeds Probably not line, thermal or radiation driven wind, so magnetic from inner disc? What is the effect of this on the disc structure?? Miller et al 2006

High frequency QPO’s 2 tiny features – give small radius..frequencies harmonically related 2:3 RESONANCE. but which?? Orbits in GR: (Stella & Vietri 1998) –v(circ, plane) –v(circ, vert) –v(ellipse, plane) Coupled by gas dynamics so can get ‘parametric’ 2:3 resonance between vertical and radial perturbations – requires a>0.95 for GBH where disc says lower… But if large scale height flow then also compressive modes then radius larger, and no strong constraint on a. Depend on M, a, R

High frequency QPO’s 2 tiny features – give small radius..frequencies harmonically related 2:3 RESONANCE. but which?? Orbits in GR (stella & vietri 1998) –f(circ, plane) –f(ellipse, plane) –f(circ, vert) Coupled by gas dynamics so can get ‘parametric’ 2:3 resonance between vertical and radial perturbations – a>0.95 (Abramovicz et al 2000) BUT disc says lower… But if large scale height flow then also compressive modes then radius larger, and no strong constraint on a (Blaes et al 2006) Depend on M, a, R

Big questions: summary Understand accretion flow at L/L Edd < 1 in GBH truncated disc, hot inner flow with jet disk to last stable orbit, no hot flow, no jet (extreme) Measure spin to test how accretion flow produces jets disk spectra - L  T 4 – depends on vertical structure broad iron lines – depends on absorption high frequency QPO’s – depends on identifing QPO Use understanding of flow to test GR – even with extremely broad lines then its fairly Einsteinian. No more than factor 2, strongly limits higher order curvature modifications to gravity

Big questions: summary Need comparable data quantity and quality on AGN in this range of L/L Edd – how does flow properties scale with mass? maximum hard X-rays from brightest low/hard state – CXB? Understand accretion flow at L/L Edd > 1 nature of ULX (GBH at high L/L Edd show low T disc) How do winds affect the disc structure NLS1’s (T Boller) use to predict AGN spectra at peak of QSO activity z~2 use to predict first BH spectra in early universe