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Blois 2008 Suzy Collin-Zahn LUTH, Observatoire de Paris Meudon AGN, MASSIVE BLACK HOLES, ACCRETION AGN, MASSIVE BLACK HOLES, ACCRETION ARE AGN FACTORIES.

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Presentation on theme: "Blois 2008 Suzy Collin-Zahn LUTH, Observatoire de Paris Meudon AGN, MASSIVE BLACK HOLES, ACCRETION AGN, MASSIVE BLACK HOLES, ACCRETION ARE AGN FACTORIES."— Presentation transcript:

1 Blois 2008 Suzy Collin-Zahn LUTH, Observatoire de Paris Meudon AGN, MASSIVE BLACK HOLES, ACCRETION AGN, MASSIVE BLACK HOLES, ACCRETION ARE AGN FACTORIES OF HIGH ENERGY PARTICLES AND PHOTONS? OR

2 Blois 2008 THE CONTEXT DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDS STRONG AND WEAK ACCRETORS CONCLUSION

3 Blois 2008 THE CONTEXT DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDS STRONG AND WEAK ACCRETORS CONCLUSION

4 Blois Active Galactic Nuclei: from quasars (L= erg/s) to Seyfert galaxies (L= erg/s), and Low Luminosity AGN (L= erg/s) RECALL OF SOME WELL-KNOWN FACTS 2. Power derived from accretion onto a supermassive black hole 3. BH present in ALL NUCLEI of galaxy, M(BH) from L=10 10 to 10 5 M , M(BH) ~ M(Bulge)/ « Unified Scheme »

5 Blois 2008 Black hole Absorbing torus Narrow line region Broad line region Accretion disk (RL or RQ) (FRI) (FRII) Wind radio galaxies LINERs

6 Blois 2008 MILLIONS OF LIGHT-YEARS Faranoff-Riley, 1974

7 Blois 2008 SOME FIDUCIAL VALUES Eddington luminosity gravitational radius: = M 8 cm ~10 -5 pc bolometric luminosity where is the accretion rate  rmaximum radiation efficiency of mass-energy conversion   for a Schwarzschild BH, R(ISCO)=6Rg   0.3 for a maximally rotating Kerr BH, R(ISCO)~1Rg = M 8 erg/s

8 Blois 2008 HOW TO FUEL BLACK HOLES? The angular momentum ( GMR) 1/2 must be transported outward! Major and minor mergers (quasars) Tidal interactions between galaxies (luminous Seyfert) Bars, bars within bars, nonaxisymmetric potentials (weak Seyfert) Dynamical friction of molecular clouds (LLAGN)… 1. At large distances (≥ 100pc) 2. At small distances (<1pc) « ACCRETION DISKS » local turbulent viscosity (MRI, possibly) local turbulent viscosity (MRI, possibly) 3. At intermediate distances Still unknown! Gravitational instability? or global transport of AM via an organized magnetic field? or global transport of AM via an organized magnetic field?

9 Blois 2008 THE CONTEXT DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDS STRONG AND WEAK ACCRETORS CONSLUSION

10 Blois 2008 In local Universe Luminous AGN : ~ 1% of all galaxies Low Luminosity AGN : ~ 40% of all galaxies The remainder 60%: dormant BH

11 Blois 2008 ACCRETION DISKS: INFLUENCE OF THE ACCRETION RATE

12 Blois 2008 Spectral distribution of Seyfert and RQQ, no radio or gamma radiation, everything is thermal! synchrotron dust cold accretion disk thermal Compton cold accretion disk thermal Compton hot corona thermal Compton hot corona thermal Compton inverse Compton inverse Compton thermal emission accretion thermal emission accretion A. STRONG ACCRETORS Observations by Sanders et al. 1989

13 Blois 2008 Thin disks, H/R <<0.1, optically thick, emit the « Big Blue Bump » Seyfert Quasars, Narrow Line Seyfert 1 (NLS1s) « slim » disks, H/R ~0.1, optically thick, radiation pressure, emit the « Big Blue Bump » I. II. « Thick » disks, H/R~1, optically thick, radiation pressure, emit soft X-rays, photons cannot escape, thus  Some low mass NLS1s ( Mo), in growing process III.

14 Blois 2008 CONTROVERSY ABOUT THICK DISKS Do these boulimic accretors exist? MHD simulations seems to show that if m >> 10 at large distance, strong outflows are expelled at smaller distance, and the accretion rate on the BH remains limited at the Eddington value..

15 Blois 2008 NO HARD X-RAYS ARE EXPECTED FROM THESE DISKS proof of the presence of a hot medium emitting the hard X-rays whose emission is « reflected » by the disk Intensity Energy in keV MCG _6_30_15 Iron K line Relativistic profile of FeK  the disk extends down to ~10Rg, and sometimes to ~1Rg  ISCO of a rapidly spinning BH BUT Fabian et al. 2006

16 Blois 2008 The reflection model: radiatively coupled disk + corona Done, Gierlinski, 2004 Same radiation coupling, but more realistic model : disk + « magnetic flares » Corona Compton- cooled by UV photons photons Disk heated by gravitational gravitational release release AND X-rays

17 Blois 2008 Optically thin, geometrically thick, hot (relativistic) disks, emitting mainly radio and X-rays, Gas falls into the BH before radiating, thus  LLAGN, radio galaxies FRI (M87..), Galactic Center B. WEAK ACCRETORS

18 Blois 2008 Inflated codona, or… …suppression of the inner regions of accretion disk The « Big Blue Bump » does not exist

19 Blois 2008 CONTROVERSY ABOUT THESE DISKS Which model for these anorexic accretors? ADAF, ADIOS, CDAF… RIAF Is there also a jet?

20 Blois 2008 Yuan, Quataert, Narayan, 2003 Synchrotron and Inverse Compton by thermal electrons Synchrotron and Inverse Compton by non-thermal electrons (jet or ADAF?) bremsstrahlung ADAF+JET FOR A « QUIESCENT » BH: THE GALACTIC CENTER measured M~ M o /yr  L (for  ~0.1) should be ~ erg/s quiescent flaring. BUT measured L~ erg/s  L/L Edd ~ ,  ~ 10 -6

21 Blois 2008 a Sgr A* Jet? ~ 1 pc F. Baganoff et al. 2003

22 Blois 2008 ADAF+JET MODEL FOR A FRI GALAXY L/L Edd ~ ADAF Jet Wu, Yuan, Cao, 2008

23 Blois 2008 CONCLUSION: BOTH STRONG AND WEAK ACCRETORS ARE RADIATIVELY INEFFICIENT BOTH STRONG AND WEAK ACCRETORS ARE RADIATIVELY INEFFICIENT DISKS MUST PRODUCE OUTFLOWS TO EVACUATE THEIR ENERGY

24 Blois 2008 THE CONTEXT DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDS STRONG AND WEAK ACCRETORS CONCLUSION

25 Blois 2008 AGN are divided in « Radio Loud » (RL) and « Radio Quiet » (RQ) Sikora, Stawarz, Lasota, 2007 BLRG LINERS RQQ RLQ SEYFERTS FRI

26 Blois 2008 Mc Lure, Dunlop 2004 With a complete sample of quasars (SDSS) Number of RLQ are less than 10% of RQQ R = Lradio(5GHz) / Lopt

27 Blois 2008 Log(L/Ledd) LINERS RQQ SEYFERTS RADIO LOUDNESS DEPENDS ON THE EDDINGTON FACTOR BLRG RLQ FRI

28 Blois 2008 LINERS, SEYFERTS RQQ RADIO LOUDNESS DEPENDS ON M(BH) BLRG RLQ FRI

29 Blois Locally RL are exclusively in elliptical galaxies, RQ in spiral galaxies DIFFERENCES BETWEEN RL AND RQ objects 2. RLs are associated with non-thermal relativistic collimated jets, RQs seem associated with thermal non-collimated winds (detected by Broad Absorption Lines and X-ray absorbers) 3. Several more subtile properties, not understood (i.e. intense FeII lines only in RQs) I. HIGH LUMINOSITY AGN WHY?

30 Blois 2008 JETS VERSUS WINDS Jets are launched at R ≤ 1000 Rg (VLBI) Winds are launched at R ≥ 10000Rg OBSERVATIONS Jets have relativistic bulk velocities and are made of relativistic particles Winds have velocities from few hundreds km/s to c/10 and consist of warm ( K) thermal gas

31 Blois 2008 Magnetic field is indispensable to explain extended jet acceleration: 1. Centrifugally driven flow 1. Centrifugally driven flow 2. Extraction of the rotational energy of the BH: field connects the BH to the disk (Blandford-Znajek, 1977) JET DRIVING MECHANISM  Jets might be linked with the spin of the BH

32 Blois 2008 BLACK HOLE SPIN 1. Even RQ AGN have spinning BH (FeK line) 2. Cosmological evolution of AGN requires large fraction of spinning BHs (mass-conversion efficiency must be > 0.06) Measured by dimensionless angular momentum a = J/Jmax = cJ/GM 2 4. It is expected that a increases with accretion AND with merger of two BHs 3. Power of the jet must increase with a 5. BHs increase with galaxy bulges, and a fraction of elliptical galaxies (large bulges) are due to the merger of spirals Elliptical galaxies favor high spin, therefore jets

33 Blois 2008 But it does not explain all: Other mechanisms must be at work 1.Environnement can play a role: 1.Environnement can play a role:spiral galaxies contain cold gas, ellipticals contain and are surrounded by hot gas 2. Geometry of the inner disk can play a role: thick or thin 3. Density profile of the circumnuclear regions can play a role: cusp or core etc… etc…

34 Blois 2008 DO THEY HAVE JETS? YES! Falcke et al; 2000 A sample of Low Luminosity AGN Compact jet structure with flat spectra observed in 40% of LLAGN (bulge) large M(BH)small M(BH) II. LOW LUMINOSITY AGN but no detailed mechanism proposed so far

35 Blois 2008 FINALLY IS THE SOLUTION THIS ONE? Radio Loud AGN Radio Quiet AGN

36 Blois 2008 Hawley, Balbus, 2002 OR ARE THE WIND AND THE JET COEXISTING? inner jets can be undetected in luminous AGN WIND JET

37 Blois 2008 CONCLUSION 3. BAD NEWS: Only a small proportion of luminous AGN have relativistic jets and non-thermal radiation 1. jets or high energy mechanisms can escape detection, if they are quenched close to the BH 4. GOOD NEWS: In low luminosity AGN (and basically all galaxies), jets and high energy processes take place close to the central BH 2. Jets in radio loud high luminosity AGN are likely driven by spinning black holes, but other mechanisms must play a role AND FINALLY, VERY LITTLE IS YET UNDERSTOOD!

38 Blois 2008

39 An exemple of a strong accretor (Ton S 180) modeled by a thick disk, M(BH)= M o, m=60 Kawaguchi, Piérens, Huré, 2003

40 Blois 2008 Caution: one defines sometimes

41 Blois 2008 Wind driving mechanism -radiation pressure driven from the disk but « shielding » of the central source necessary -centrifugally driven from disks threated by an open magnetic field - thermally or hydrodynamically driven from the hot corona sketch of a disk wind, centrifugally and/or radiatively accelerated


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