A synthetic view of AGN evolution and
Supermassive black holes growth
Andrea Merloni
Excellence Cluster Universe, Garching,
Max-Planck Institut für Extraterrestrische Physik
With
Sebastian Heinz (Univ. of Wisconsin)
5GHz, VLA image of Cyg A by R. Perley
Leiden 25/11/2009
Outline
• Accretion modes
• XRB analogy and scaling laws
• Cosmological evolution (z<3-4)
• Continuity equation, mass and redshift dependence of the
fuelling rate
• Kinetic vs. radiative feedback
The standard view of the AGN-galaxy connection
•Image credit: Aurore Simonnet, Sonoma State University
A logarithmic view of the AGN-galaxy connection
Binding Energies
Eb,≈4  1048 ergs
Eb,BH,8≈1061 ergs
Eb,gal,11≈1059 ergs
Eb,Coma≈1064 ergs
Bulge
RB
TOR [IR]
Jet
[VLBI/-rays]
BLR
Rvir,12
[Opt/UV spec.]
AD [X-rays]
Rsub
Risco
disc
Log R/RS
0
1
2
3
4
5
6
7
8
9
Log R/pc
-5
-4
-3
-2
-1
0
1
2
3
4
Q: How does the feedback loop close?
Or
Is the accretion (and energy release) mode of an AGN
dictated by the internal energy of the accreting gas, or
simply by its overall rate?
Hot vs. cold? Low vs. high mdot? XRB examples
GX 339-4 Fender et al. 1999
XRB: low/hard state as jet-dominated RIAF
• Strong correlation between radio and X-ray emission in low/hard state (Gallo+
2003)
• Assume jet power LKin~ Accretion rate
• Independent of geometry and jet acceleration mechanisms, it can be shown that
LR~M17/12mdot17/12 for flat radio spectra from compact, self-absorbed synchrotron
• The observed radio-X-ray correlation (LR~LX0.7) implies:
• X-ray emission is radiatively inefficient (LX~Mdot2)
• LKin ~ LR1.4
Falcke and Biermann ’96; Heinz and
Sunyaev 2003; Merloni et al 2003
The Fundamental Plane of active black holes
The Fundamental Plane of active black holes
Merloni, Heinz & Di Matteo (2003)
Gültekin et al. (2009)
AGN feedback: evidence on cluster scale
• 1 Msec observation of
the core of the Perseus
Cluster with Chandra;
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
ICM
• Radio maps reveal close
spatial coincidence
between X-ray
morphology and AGNdriven radio jets
Fabian et al. 2006
(Birzan et al. 2004, 2008;
Allen et al. 2006; Rafferty
et al. 2006, etc.)
Core Radio/LKin relation
Log Lkin=0.81 Log L5GHz +11.9
Slope=0.81
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)
Low Power AGN are jet dominated
Kinetic power Radiative power
dominates outputdominates output
• The observed slope
Log
(0.49±0.06) is consistent
with radiatively inefficient
“jet dominated” models
Log Lkin/LEdd=0.49 Log Lbol/Ledd - 0.78
Log
Merloni and Heinz (2007)
Powerful jets: Clues from FERMI Blazars
Ghisellini et al. 2009
Basic scaling laws (working hypothesis)
LLAGN (L/Ledd<0.01)
LR  LX0.6-0.7 M0.7-0.8
LKIN  LR0.7-0.8
LKIN /LEDD LX/LEDD0.5
Powerful Jets (L/Ledd>0.01)
LKIN,JEt ~ Lbol
Accretion diagram for LMXB & AGN
Model parameter
New “Blazar Sequence”
Ghisellini and Tavecchio (2009)
LK (low-kinetic; LLAGN, FRI)
HK (high-kinetic; RLQ, FRII)
HR (high-radiative; RQQ)
(Blandford & Begelman 1999, Körding et al. 2007, Merloni and Heinz 2008)
A synthetic view of SMBH growth:
the “radiative” sector
Continuity equation for SMBH growth
Need to know simultaneously mass function (M,t0)
and accretion rate distribution F(dM/dt,M,t) [“Fueling function”]
=0
luminosity function
mass function
Cavaliere et al. (1973); Small & Blandford (1992); Marconi et al. (2004); Merloni (2004)
Bivariate distributions
Mass function of Emission Line AGN
Z=0.3
NLAGN
BLAGN
Greene and Ho 2007
Bivariate distributions
NLAGN
BLAGN
Z=1.0
Bivariate distributions
NLAGN
BLAGN
Z=2.0
Mass & Fueling functions evolution
Log M=7
z=4
Log M=9
z=0.1
Gal. growth times [Gyr]
BH growth times [Gyr]
Anti-hierarchical growth of structures
Perez-Gonzalez et al. 2008
1M$ Question:
What (if any) is the physical link between these two apparently related
evolutionary paths?
The Kinetic Energy output of SMBH
Accretion diagram for LMXB & AGN
Model parameter
LK (low-kinetic; LLAGN, FRI)
HK (high-kinetic; RLQ, FRII)
HR (high-radiative; RQQ)
(Blandford & Begelman 1999, Körding et al. 2007, Merloni and Heinz 2008)
SMBH growth: weighting modes
Log Lkin= 45.2 x 0.81 Log (P1.4,core /1025)
(Merloni & Heinz 2007)
Log Lkin= 44.1 x 0.4 Log (P1.4 /1025)
(Birzan et al. 2004, “cavity power”)
Log Lkin= 44.2 x 0.8 Log (P1.4 /1025)
(Willott et al. 1999, “synchrotron power”)
Heinz, Merloni and Schwaab (2007)
Körding, Jester and Fender (2007)
Cattaneo and Best (2009)
SMBH growth: weighting modes
Log Lkin= 45.2 x 0.81 Log (P1.4,core /1025)
(Merloni & Heinz 2007)
Log Lkin= 44.1 x 0.4 Log (P1.4 /1025)
(Birzan et al. 2004, “cavity power”)
Log Lkin= 44.2 x 0.8 Log (P1.4 /1025)
(Willott et al. 1999, “synchrotron power”)
Heinz, Merloni and Schwaab (2007)
Körding, Jester and Fender (2007)
Cattaneo and Best (2009)
Conclusions
• AGN obey simple scaling laws, at least for low accretion rates
• Main parameters are M and L/LEdd
• SMBH grow with a broad accretion rate distribution (be very careful when
discussing AGN fractions, AGN lifetimes, etc.)
• The anti-hierarchical trend is clearly seen in the low-z evolution of SMBH
mass function.
• Physically motivated scaling Lkin ~ Lcore,5GHz0.7-0.8
• Feedback from “Low-luminosity AGN” is 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).