Download The relation among black holes, their host galaxies and AGN activity

INAF
ISTITUTO NAZIONALE DI ASTROFISICA
NATIONAL INSTITUTE FOR ASTROPHYSICS
The relation among black holes,
their host galaxies and AGN
activity
Alessandro Marconi
INAF-Osservatorio Astrofisico di Arcetri
Galaxies and Structures
through Cosmic Times
Venice, March 26-31, 2006
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)
The Local BHMF from MBH – Lbul/σe
Galaxy
Luminosity Function
per Morphological Type
+ Bulge/Total correction
Bulge (Spheroid)
Luminosity Function
+ Faber-Jackson
relation
Galaxy
Velocity Function
(SDSS, Sheth et al. 2003)
+ MBH-σe relation
+ MBH-Lbul relation
Black Hole Mass Function
e.g. Salucci et al. 1998,
Marconi & Salvati 2001
e.g. Ferrarese 2002,
Aller & Richstone 2003
e.g. Yu & Tremaine 2002,
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 luminosity
 Φ(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
Hard-X LF
Soft-X LF
 Heavily obscured
Compton-thick AGN
are missing
X-ray background
spectrum
Qso LF
X-ray Background constraints
 XRB models provide the
total numbers of
Compton-thin + Comptonthick 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  whole
AGN 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
50% of final mass
 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.
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