1. Cosmological evolution of supermassive black holes and AGN: a synthesis model for accretion and feedback
Andrea Merloni
Excellence Cluster Universe &
Max-Planck Institut für Extraterrestrische Physik
Garching, Germany
Sebastian Heinz
Univ. Wisconsin, Madison, USA
“The inner Kiloparsec”, Ierapetra, Crete, 6/6/2008

2. 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?
Stellar physics, SN explosions, GRB
ΩSMBH≈2.710-6
Accretion over cosmological times,
Active Galactic Nuclei, galaxy evolution
Sgr A*
M87
Ωbaryon≈4.510-2 ; Ωstars≈2.510-3

3. Outline: What do we know about evolution of SMBH population?
Evolution of mass and accretion rate density
Constraints on radiative efficiency and avg. BH spin
An “AGN synthesis model”
Eddington ratio distributions, AGN fractions, etc.
Constraints on AGN downsizing
Mapping the different accretion modes
Radiative vs. kinetic energy output and feedback

4. Synthesized backgrounds and AGN census
Marconi et al. 2004
Hard X-rays (2-10 keV)
Soft X-rays (0.5-2 keV)
Optical/UV
Gilli, Comastri, Hasinger 2007

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

6. 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

7. (Normalized SMBH mass density)
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
BHAR(z) =
(Normalized SMBH mass density)

8. Accretion power and star formation
Hopkins and Beacom (2006)
Brusa et al. 2008
Best constraints on high-z (z>3) X-ray selected AGN evolution (XMM-COSMOS)
Absorption-corrected X-ray LF, a, +
contribution of Compton thick AGN from XRB synthesis model (~20-30%) of total grown mass
Merloni and Heinz 2008

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

10. 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)
0.065/[0 (1+lost)] rad 0.069/[0 (1- i +lost)]
Merloni and Heinz 2008

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

12. Constraints on avg. SMBH spin a*
0.065/[0 (1+lost)] rad 0.069/[0 (1- i +lost)]
(Not symmetrized!, see King’s talk)

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

14. 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)

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

16. “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)

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

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

19. Mass weighted avg. Eddington ratio evolution
We can follow the history of progenitors of local black holes

20. AGN downsizing: changing accretion modes
SMBH 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 (misleading!) Cosmology jargon: Quasar mode vs. Radio mode (explosive vs. gentle)

21. Radio cores scaling with M and mdot
A “fundamental plane” of active BHs [Merloni et al. 2003; Falcke et al. 2004]
LR/1.3 1038 M1.38
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

22. 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 (red), (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

23. 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
Merloni and Heinz (2007)

24. 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)

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

26. Core Radio/LKin relation: effects of beaming
Log Lkin=0.81 Log L5GHz +11.9
Slope=0.81
Slope=0.54
Observed LR (beaming)
Derived from FP relation
Monte Carlo simulation:
Statistical estimates of
mean Lorentz Factor ~8
Not a distance effect:
partial correlation analysis
Pnul=2 10-4
Merloni and Heinz (2007)

27. AGN Kinetic Luminosity function
Körding, Jester and Fender (2007); Merloni and Heinz (2008)

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

29. Kinetic efficiency of growing black holes

30. Conclusions
SMBH grow with a broad accretion rate distribution (be very careful when discussing AGN fractions, AGN lifetimes, etc.)
Most of SMBH growth occurred in radiatively efficient episodes of accretion. Very strong constraint on rad. efficiency (spin)
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 % (but strongly dependent on BH mass and redshift).
Do we need Quasar winds/outflow for feedback at all?

31. Hubble Heritage Project
The M87 jet
Hubble Heritage Project