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The relation among black holes, their host galaxies and
AGN activity
INAFISTITUTO NAZIONALE DI ASTROFISICA
NATIONAL INSTITUTE FOR ASTROPHYSICS
Galaxies and Structures through Cosmic TimesVenice, March 26-31, 2006
Alessandro MarconiINAF-Osservatorio Astrofisico di
Arcetri
In collaboration with …
Andrea Comastri (INAF – Bologna, I) Roberto Gilli (INAF – Bologna, I) Günther Hasinger (MPE, Garching, D) Leslie Hunt (INAF – IRA, Firenze, I) Roberto Maiolino (INAF – Arcetri, Firenze, I) Guido Risaliti (INAF – Arcetri, Firenze, I) Marco Salvati (INAF – Arcetri, Firenze, I)
Supermassive Black Holes Supermassive BHs (106-1010 M) are
detected in 30-40 NEARBY (D<100 Mpc) galaxies (e.g. Ferrarese & Ford 2005).
MBH correlates with Lsph/Msph (Kormendy & Richstone 1995, Magorrian et al. 1998, McLure & Dunlop 2002, Marconi & Hunt 2003) and σe
(Ferrarese & Merritt 2000, Gebhardt et al. 2000).Supermassive BHs likely present in all
galaxies.Supermassive BHs are also expected as
“Relics” of AGN activity.Are the local supermassive BHs consistent
with being AGN relics?
The Relation between Local Black Holes and AGN
relics Compare the mass density of local
BHs with that of AGN relics (e.g. Soltan 1982, Fabian & Iwasawa 1999, Elvis, Risaliti & Zamorani 2002)
Compare the local BH Mass Function with the mass function of relic BHs (e.g. Yu & Tremaine 2002, Ferrarese 2002, Marconi et al. 2004, Merloni 2004, Shankar et al. 2004)
+ M+ MBHBH--σσee relation relation
+ Faber-Jackson+ Faber-Jackson relationrelation
Galaxy Galaxy Velocity FunctionVelocity Function
The Local BHMF from MBH – Lbul/σe
e.g. Salucci et al. e.g. Salucci et al. 1998, 1998, Marconi & Salvati Marconi & Salvati 20012001
e.g. Yu & Tremaine e.g. Yu & Tremaine 2002, 2002,
Black Hole Mass Black Hole Mass FunctionFunction
+ M+ MBHBH-L-Lbulbul relation relation
+ Bulge/Total correction+ Bulge/Total correction
Bulge (Spheroid)Bulge (Spheroid)Luminosity FunctionLuminosity Function
GalaxyGalaxyLuminosity FunctionLuminosity Function
per Morphological Typeper Morphological Type
e.g. Ferrarese e.g. Ferrarese 2002,2002,Aller & Richstone Aller & Richstone 2003 2003
(SDSS, Sheth et al. 2003)(SDSS, Sheth et al. 2003)
The local Black Hole Mass Function
Using MBH-Lbul and MBH-σe provide consistent BH mass functions (differences included in shaded area which indicates uncertainties)
ρBH ≃ 4.1+1.9-1.4 ×105 M Mpc-3 (cf.
Merritt & Ferrarese 2001, Ferrarese 2002, Shankar et al. 2004)
In summary: 3-5 ×105 M Mpc-3
(see Ferrarese & Ford 2005 for a review)
The AGN BH Mass Function
Assume accretion onto BH as powering mechanism of AGN to link LAGN with MBH
[L= λ MBHc2/tE= ε (dM/dt)c2]
Use the continuity equation (Cavaliere et al. 1971) to relate the BH Mass function N(MBH) to the AGN Luminosity function Φ(L)
Critical issues: L is the TOTAL accretion luminosityΦ(L) is the luminosity function of ALL AGNs
(observations provide Φ only for a subset of the AGN population)
Local BHMF vs Relics BHMF
The relic BHMF is a function of the band in which AGN are selected.
Even the hard (2-10 keV) XLF does not sample the whole AGN pop
Heavily obscured Compton-thick AGN are missing
X-ray background spectrum
Qso LF
Hard-X LF
Soft-X LF
X-ray Background constraints
XRB models provide the total numbers of Compton-thin + Compton-thick AGN
Two options explored:M1: R =
obscured/unobscured AGN ratio = constant M2: R decreasing with
luminosity
Gilli, Comastri, Hasinger 2006 in prep.
Local BHMF vs Relic BHMF
Correction for Compton-Thick sources from XRB models wholeAGN pop considered
The only free parameters are the accretion efficiency and Eddington ratio
Assume:ε=0.1 (L= ε dM/dt
c2)λ=1 (L= λ LEdd)
Radiative Efficiency and Fraction of Eddington
luminosity Efficiency and fraction
of Eddington luminosity are the only free parameters!
Determine locus in ε-λ plane where there is the best match between local and relic BHMF!
ε=0.04-0.10 λ=0.08-0.5 which are consistent with common ‘beliefs’ on AGNs
Local BHMF vs Relic BHMF
Local and Relic BHMFs are in agreement without considering merging.
Either merging of BHs is negligible for z<3 or it does not modify significantly the BHMF (e.g. Granato et al. 2004, Menci et al. 2004, Haiman, Ciotti & Ostriker 2004).
with best ε and λ values …
Anti-Hierarchical BH growth This is qualitatively
consistent with models of galaxy formation (e.g. Menci et al. 2003, Granato et al. 2003)
Big BHs form in deeper potential wells they form first.
Smaller BHs form in shallower potential wells and are more subjected to feedback effects (star form., AGN), they form later and take more time to grow.
See also Merloni 2004.
50% of final mass
Conclusions The local BH mass density is ρBH = 4.1±1.5 ×105 M Mpc-
3. The local BH mass function and the BH mass function of
AGN relics are in good agreement with standard ε and λ values (ε ~ 0.1, λ ~ 1.0).
Merging of BH’s either is not important or it does not significantly alter the relic BHMF, at least at z<3.
The BH growth is anti-hierarchical: smaller BH’s, MBH< 107 M, grow at lower redshifts, z<1, with respect to more massive ones, z=1-3.
Local BH's grew during AGN phases in which accreting matter was converted into radiation with ε = 0.04-0.1 and emitted at a fraction λ = 0.08-0.5 of the Eddington luminosity.
Marconi et al. 2004, 2006 in preparation