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Cosmological growth of supermassive black holes: a synthesis model for accretion and feedback

Cosmological growth of supermassive black holes: a synthesis model for accretion and feedback. Andrea Merloni Max-Planck Institut für Extraterrestrische Physik Garching, Germany. OAR Monteporzio, 17/3/2008. Accretion over cosmological times, Active Galactic Nuclei, galaxy evolution.

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Cosmological growth of supermassive black holes: a synthesis model for accretion and feedback

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  1. Cosmological growth of supermassive black holes: a synthesis model for accretion and feedback Andrea Merloni Max-Planck Institut für Extraterrestrische Physik Garching, Germany OAR Monteporzio, 17/3/2008

  2. Accretion over cosmological times, Active Galactic Nuclei, galaxy evolution Stellar physics, SN explosions, GRB Sgr A* M87 Black Holes in the local Universe Ω*BH≈710-5[Fukugita & Peebles (2007)] • Density of stellar mass BHs increases w/galaxy mass • How does the high-mass (Supermassive) peak grow? ΩSMBH≈2.710-6 Ωbaryon≈4.510-2 ;Ωstars≈2.510-3

  3. This talk: • What do we know about evolution of SMBH population (mass function, accretion rates, etc.) • A lot! (up to z~4-5) • Evolution of mass and accretion rte density • Constraints on radiative efficiency and avg. BH spin • AGN downsizing: the role of accretion modes • Anti-hierarchical evolution (downsizing) • AGN synthesis models • Radiative vs. kinetic energy output • Where are the frontiers? • Obscured AGN • High-z AGN, first BH • Iron line spectroscopy: spin evoluton

  4. LEdd=4πGMcmp/ Accretion efficiency, Eddington limits • In order to get close (R), a particle of mass m must get rid of energy Elib = GMBHm/R • Efficiency of accretion in liberating rest mass energy: • =Elib/mc2=Rg/2Rin, with Rg=GMBH/c2GR → 0.06<h(a)<0.42 • BHs grow by accreting mass: Powerreleased=[/(1-)](dMBH/dt)c2 • Self-regulating luminosity • LEdd,es = 1.3 x1038 (MBH/Msun)[XRB, AGN] • LEdd,= 8x1053(E /50MeV)-2(MBH/Msun)[GRB]

  5. AGN and Cosmology: (very) early developments Longair 1966

  6. AGN and Cosmology: a shift of paradigm • BH/Galaxy Scaling relations discovered in 2000 (HST) • Nowadays QSOs/AGN can: • Regulate galaxy formation • Stop cooling flows • “produce” early type galaxies with the right colors • Keep the universe ionized • QSOs/AGN tracks the history of star formation in the Universe Gebhardt et al. 2000; Ferrarese et al. 2000; Greene et al. 2005

  7. AGN and Cosmology: a shift of paradigm Hopkins and Beacom (2006) • BH/Galaxy Scaling relations discovered in 2000 (HST) • Nowadays QSOs/AGN can: • Regulate galaxy formation • Stop cooling flows • “produce” early type galaxies with the right colors • Keep the universe ionized • QSOs/AGN tracks the history of star formation in the Universe Merloni et al. 2008

  8. Marconi et al. 2004 Recent progresses in AGN activity census Hard X-rays (2-10 keV) Soft X-rays (0.5-2 keV) Optical/UV Gilli, Comastri, Hasinger 2007

  9. Radiative efficiency BH growth rate Accretion rate Hopkins et al 2006 Bolometric corrections robustness Crucial: varying X-ray bolometric correction with luminosity (Marconi et al 2004)

  10. Note: radiative efficiency vs. accretion efficiency accretion efficiency (BH spin) radiative efficiency Non Spinning BH Maximally Spinning BH Determined by the complex physics of gas accretion

  11. BHAR(z) = Integral constraints • Soltan (1982) first proposed that the mass in black holes today is simply related to the AGN population integrated over luminosity and redshift (Normalized SMBH mass density)

  12. Convergence in local mass density estimates       Graham and Driver (2007)

  13. Perez-Gonzalez et al.(2007) SMBH vs TOTAL stellar mass densities rad=0.07 3 1 z

  14. Begelman & Rees: Gravitiy’s fatal attraction 0.065/[0(1+lost)] rad 0.069/[0(1- i +lost)] Constraints on avg. radiative efficiency rad 0=BH,0/(4.2x105) i=BH(z=zi)/BH,0 (Input from seed BH formation models needed!) lost=BH,lost/BH,0 • (Mass density of SMBH ejected from galactic nuclei due to GW recoil after mergers) Merloni and Heinz 2008

  15. Constraints on avg. SMBH spin a* 0.065/[0(1+lost)] rad 0.069/[0(1- i +lost)]

  16. Constraints on avg. SMBH spin a* (SMBH more easily ejected If avg. spin higher

  17. AGN downsizing AGN/SMBH downsizing: clues from X-rays Ueda et al. 2003; Fiore et al. 2003; Barger et al. 2005; Hasinger et al. 2005

  18. Continuity equation for SMBH growth Cavaliere et al. (1973); Small & Blandford (1992); Marconi et al. (2004) 1- Need to know simultaneously mass function M(M,t0) and accretion rate distribution 2- At any z (or t), it is possible to combine mass function and bolometric luminosity function to calculate accretion rate distribution Picture from Di Matteo et al. (2007)

  19. Mass function must get narrower with z Solved continuity equation backwards in time L/Ledd function gets wider Merloni and Heinz 2008.

  20. “Active” BH Fractions/Mass Sensitivity curves • Consequences of broad accretion rate distributions: • Number density and mass functions of AGN are very sensitive to survey selection function • The concept of “active” BH must be defined observationally Merloni and Heinz (2008)

  21. 23,000 type 2 AGN at z<0.1 ~ 3 Log MBH Heckman et al. 2004 SMBH downsizing The anti-hierarchical evolution at low z seems reversed at high z Growth Time

  22. SMBH downsizing 1/ Future work: comparison with galaxies growth Growth Time AEGIS Survey: Star forming galaxies Noeske et al. 2007

  23. SMBH downsizing 1/ Future work: comparison with galaxies growth Growth Time AEGIS Survey: Star forming galaxies Noeske et al. 2007

  24. Radiated energy density by BH mass We can follow the history of progenitors of local black holes Merloni and Heinz (2008)

  25. AGN downsizing: changing accretion modes • SMBH must accrete at lower (average) rates at later times • Accretion theory (and observations of X-ray Binaries) indicate that • The energy output of an accreting BH depends crucially on its accretion rate • Low-accretion rate systems tend to be “jet dominated” • In the recent Cosmology jargon: Quasar mode vs. Radio mode (explosive vs. gentle)

  26. BH transients: window on accretion physics GX 339-4 Fender et al. 1999

  27. LR/1.3 1038 M1.38 Radio cores scaling with M and mdot A “fundamental plane” of active BHs [Merloni et al. 2003; Falcke et al. 2004] Open triangles: XRB Filled squares: AGN Very little scatter if only flat-spectrum low-hard state sources are considered (Körding et al. 2006) Maccarone et al. 2003

  28. AGN feedback: evidence on cluster scale • 1 Msec observation of the core of the Perseus Cluster with the Chandra X-ray Observatory • True color image made from 0.3-1.2 (red), 1.2-2 (green), 2-7 (blue) keV photons • First direct evidence of ripples, sound waves and shocks in the hot, X-ray emitting intracluster gas • Radio maps reveal close spatial coincidence between X-ray morphology and AGN-driven radio jets Fabian et al. 2006

  29. Low Power AGN are jet dominated • By studying the nuclear properties of the AGN we can establish a link between jet power and accretion power • The observed slope (0.50±0.045) is perfectly consistent with radiatively inefficient “jet dominated” models (see E. Churazov’s talk) Cyg X-1 Log Lkin/LEdd=0.49 Log Lbol/Ledd - 0.78 Merloni and Heinz (2007)

  30. Accretion diagram for LMXB & AGN Model parameter HK (high-kinetic; RLQ) LK (low-kinetic; LLAGN, FRI) HR (high-radiative; RQQ) (Blandford & Begelman 1999, Merloni 2004, Körding et al. 2007)

  31. SMBH growth Most of SMBH growth in radiatively efficient mode 20-26%   0.065-0.07 Marconi et al. (2004) Merloni 2004; Merloni et al. 2008

  32. Kinetic Energy output and SMBH growth Körding, Jester and Fender (2007); Merloni and Heinz. (2008)

  33. Kinetic Energy output by SMBH mass

  34. Kinetic efficiency of growing black holes

  35. Conclusions • SMBH grow with a broad accretion rate distribution • Most of SMBH growth occurred in radiatively efficient episodes of accretion. • The anti-hierarchical trend is clearly seen in the low-z evolution of SMBH mass function. Reversal at higher z? • Feedback from “Low-luminosity AGN” are most likely dominated by kinetic energy • The efficiency with which growing black holes convert mass into mechanical energy is 0.3-0.5% (but strongly dependent on BH mass and redshift).

  36. Open questions • Large, wide-area surveys (eROSITA) • Tighten NH(z,L) • Bolometric corrections: SED variance • Hard X-ray spectroscopy (Simbol-X) • Where are the Compton Thick AGN? • Spin properties of AGN from iron line spectroscopy • Deep and very deep surveys (XEUS) • Seed Black holes distribution

  37. The M87 jet Hubble Heritage Project http://heritage.stsci.edu/2000/20/index.html

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