Transcript Black Hole Demographics

Laura Ferrarese
Rutgers University
Lecture 5: SBH
Demographics
SIGRAV Graduate School in Contemporary
Relativity and Gravitational Physics
Lecture Outline
1. The First Clue: Supermassive Black Hole Masses and the Total Luminosity of
the Host Bulge
2. The MBH- Relation
3. Black Holes and Dark Matter Haloes (?)
4. Applications
SBHs and Bulges
 Kormendy & Richstone (1995) first pointed out that given the eight SBH detections
available at the time, SBH masses correlate with the total blue magnitude of their host
bulge (meaning the entire galaxy in the case of ellipticals).
 This suggests a connection between SBH and bulge masses.
Kormendy & Richstone 1995, ARA&A, 33, 581
SBHs and Bulges
 This correlation was further elaborated by Magorrian (1998), who published a correlation
between SBH and bulge masses based on axysimmetric, 2-I dynamical models.
 The ratio between SBH and bulge mass was measures to be MBH/Mbulge~0.6%.
 (km s-1)
 (km s-1)
Data from Magorrian et al. (1998)
R (arcsec)
 (km s-1)
R (arcsec)
R (arcsec)
SBHs and Bulges

We have discussed several problems affecting the
Magorrian analysis:



the use of 2-I models might bias the mass
estimates
perhaps more importantly, the models were
applied to data which did not resolve the SBH
sphere of influence, and therefore contained no
information about the central SBH.
What if we only include masses which are:


based on data that resolves the SBH sphere of
influence.
are derived from 3-I models
Note that these two conditions do not assure that the
mass estimate is reliable, but at least it’s a starting point!
 Two things happen (Merritt & Ferrarese 2000):


the average MBH/Mbulge ration decreases (from
~0.6% to ~0.1%). This is because most of the
Magorrian SBH masses are overestimates.
The scatter in the relation, however, does not
really seem to change.
SBHs and Bulges

Is the scatter in the MBH-Mbulge relation really as large as it seems?
 McLure & Dunlop (2002) suggest that the scatter depends (perhaps through systematic
errors in the bulge magnitudes) on the Hubble type of the host galaxy.
 They include (almost) only (but not all) elliptical galaxies, and use R-band instead of B-band
magnitudes.
Ferrarese 2002/astro-ph/0203047
McLure & Dunlop 2002
SBHs and Bulges
 Marconi & Hunt (2003, astro-ph/0304274) found that a tighter correlation is obtained if K

band magnitudes, instead of B-band magnitudes, are used.
This is not surprising: if it is the mass of bulge to drive the correlation, the mass is better
traced in the K rather than in the B-band. Also, the B-band magnitudes commonly used are
likely very inaccurate, especially for spiral bulges.
2
The bulge mass is simply the virial mass given by:
1
Mbu lge  kre e
G
where re and e are the bulge effective radius and velocity dispersion respectively. k
depends on the dynamical state of the system, and is therefore not likely (but was assumed
to be) constant for all galaxies.

SBHs and Bulges
 A tighter relation is obtained if the bulge velocity dispersion  is substituted to the bulge
blue magnitude (Ferrarese & Merritt 2000 and Gebhardt et al. 2000):
Gebhardt et al. 2000
Ferrarese 2002
M BH
M
4.60.5


c
 (1.7  0.3) 108
1 
200km
s


2

r  0.72

The Discovery of the M Relation
 What is relevant about the MBH relation? After all, bulge luminosity and velocity
dispersion are known to correlate through the “Faber-Jackson” relation:
From Faber & Jackson 1976, ApJ, 204, 668
 Therefore, the existence of the MBH-Mbulge relation, combined with the Faber-Jackson
relation, implies that MBH must correlate with .
 The significance of the MBH relation lies in its small scatter, which is smaller than the
scatter in either the MBH-Mbulge or Faber Jackson relations. This indicates that the MBH
relation is more fundamental.
What if only BH detections obtained
from the highest resolution data are
used?
(MW, H20, HST data)
SBH Mass vs. Bulge Velocity
Dispersion
SBH Mass vs. Bulge Magnitude
The “Discovery” of the M Relation
SBHs and the Concentration of Bulge
Light
 Graham et al. (2001) found evidence of a strong correlation between the concentration of
bulges and the mass of their central SBH.



whatever mechanisms are responsible for the formation of the SBH, they not only
control the bulge luminosity, but also the distribution of bulge light.
CONS: Use of the concentration index might not be applicable to studies of
morphologically disturbed galaxies or dominant cD galaxies with extended
envelopes.
PROS: Measuring central mass concentration is relatively easy, even for galaxies at
large distance.
SBHs and the Concentration of Bulge
Light
 Could we have “expected” a correlation between SBH masses and concentration of bulge
light to exist? Probably yes:
The fundamental plane for 226 galaxies in 10 clusters
(from Jorgensen et al. 1996, MNRAS, 280, 167
 However, just as is the case for the MBH relation, the MBHC relation seems to be tighter,
and therefore more fundamental, than the relations from which it can be “built”
The M- Relation - Why is it
Interesting?
The tightness of the MBH relation must be telling us something fundamental about the
connection between BHs and bulges.
Simple interpretation: A constant fraction of the bulge mass is channeled into the BH
(Ferrarese & Merritt 2000)
MBH 



Mbulge
Lbulge (M/L)bulge
Lbulge Lbulge 1/4
Lbulge 5/4  (4)5/4  5
(e.g. Jorgensen et al. 1996)
(Faber Jackson relation)
But: a) the MBH  relation is tighter than the relation between MBH and mass (or
luminosity).
b) Even if a MBH - Mbulge relation were setup in the early universe it is difficult to
imagine
how it could have survived in the face of mergers.
An additional feedback mechanism must act to directly connect black hole mass to
stellar velocity dispersion.
Feedback Mechanisms
Galaxy Mergers
Kauffman
Haehnelt
Burkert &&Silk
(2001)2000
Semi-analytical
of merger
starbursts
in CDMfor
hierarchical
models.
The cooling of
Self regulated models
BH growth
within adriven
major-merger
scenario
the formation
of spheroids.
gas
fallsfollowing
in duringmerging
mergersisishalted
assumed
to the
be balanced
by energy
input
SNe.regions
BHthat
growth
when
onset of star
formation
in from
the outer
of the disk limits the amount of gas available for accretion.
MBH ~ >2
MBH ~ 4-5
Arbitrarily steep slopes can be produced; the model does not reproduce the small scatter in the
MThe
 relation
tightness of the M relation is not explained
Galaxies
Silk & Rees (1998), Haehnelt, Natarajan & Rees (1998)
The formation and accretion history of SMBHs is determined by accretion at the center of a gravitationally
unstable self-gravitating disk in the core of a newly-formed dark matter halo.
(1998)
Sellwood
&
(1999)
An upper limit to BH growth
willMerritt
beMoore
reached
when the emitted energy exceeds the energy deposition rate
The
BH shapes
the
distribution
ofwind
stellar
BHdisk.
growth
driven
by
bar instabilities
which
develop
during the
necessary to unbind the
The
back
reaction
of the
radiation
willorbits
produce
a dramatic decrease in the
destroying
triaxiliaty
in
less
than
a
Hubble
time
early
stages
of
galaxy
formation.
accretion rate.
< -19 mag)
ellipticals
if Mof
/Mgaldisk
~ the
When thefor
BHfainter
mass(M
reaches
~1.5%
the mass
BHthe
3%.and
Once
the
non-axisymmetric
component
is galaxy
weakens
the
accretion
(Eddingtonbar
luminosity)
(dynamical
time)halts.
= binding energy
of the
weakened, further growth of the BH is halted.
No
BHs should
galaxies;
4 GM
 be found
Rbulgein/DM dominated
≈ GM2bulge
/Rbulge
BH mp/T
4
a much
M
/M
than
Predicts aRequires
much larger
MBHlarger
/Mbulge
than
observed
 BH≈ bulge
 Rbulge/G
2
5
5
observed
MBH ≈ (T / mp 4 cG )  ≈ 
Neglects star formation, deviations from spherical symmetry, mergers.
Black Hole
SBH Formation from the The MBH-
Relation

Constrain models of SBH/galaxy formation
Silk & Rees 1998; Haehnelt, Natarajan & Rees 1998; Kauffmann & Haehnelt 2000;
Haehnelt & Kauffmann 2000; Burkert & Silk 2001; Ciotti & van Albada 2001; Fabian et al.
2001; Cavaliere & Vittorini 2001; Portegies-Zwart & McMillan 2002; MacMillan & Henriksen
2002; Zhao et al. 2002;Volonteri, Haardt & Madau 2002; Islam,Taylor & Silk 2002; Wyithe &
Loeb 2002, 2003.
Haehnelt & Kauffmann 2000
SBH Demographics from the MBH- Relation:
I
 Compare the SBH mass function in high redshift quasars and local quiescent galaxies:


Learn about the existence/evolution of obscured quasars
Constrain the accretion
Merritt & Ferrarese 2001
Magorrian et al. 1998
Merritt & Ferrarese (2001):
 MBH derived from the MBH relation
 Mbulge from Magorrian et al. (1998)
Mass density in local Black Holes:
x = MBH /Mbulge ~ 0.13%
rbulge ~ 3.7108 M Mpc-3
(Fukugita et al. 1998)
r ~ 4.9105 M Mpc-3
SBH Demographics from the MBH- Relation II
Ferrarese 2002a (astro-ph/0203047)
1) Schechter Luminosity Function (e.g.
Marzke et al. 1998)
 L   L / L dL

(L)dL  0   e
L
L 
2) Faber-Jackson relation (e.g. Kormendy &
Illingworth 1993)
L  a
b
M  k
n
3)MBH relation
b(  1)
 n
( M / M ) b / n
b  M
(M)dM  0  
n M 
e
dM
M
Where M* must incorporate a term
accounting for the ratio between bulge and
total luminosity for galaxies of different
Hubble types (see also Merritt & Ferrarese
2001; Aller & Richstone 2002)
Comparison of SBH Mass Functions
 Once the contribution of obscured AGN is accounted for, the cumulative SBH mass density
in quasars is larger, by a factor 2, than the one measured in local quiescent galaxies.
 The SBH mass densities are different for the quasar and quiescent galaxy population. This
seems to be significant at least at the high mass end.
Ferrarese 2002a
astroph/0203047
(See also Yu & Tremaine
2002)
Comparison of SBH Mass Functions
Yu & Tremaine (2002): Cumulative mass density for Early Type galaxies from SDSS sample.
r(> M, total) = 1.44 r(> M, Early)=(3.3 0.5)105 M Mpc3 (for H0 = 75 km s1 Mpc1)
(Although using the MBH  L relation gives 5.8105 MMpc3)
Yu & Tremaine 2002
(H0 = 65 km s1 Mpc1)
Quasars
Early Type
Galaxies
Interpretation
 For MBH > 108 M The SBH mass function in local quiescent galaxies is not consistent
(in particular, it is lower) with the high-z quasar luminosity function derived from
optical surveys if the accretion efficiency is =0.1
 Higher (=0.2) accretion efficiencies might apply to the more massive SBHs, i.e.



massive SBHs are rapidly rotating (Yu & Tremaine 2002; Elvis, Risaliti &
Zamorani 2002).
Quasars might have super-Eddington luminosities (cfr. Begelman 2001, 2002)
SBHs might be ejected from galactic nuclei as a consequence of merging (Yu &
Tremaine 2002; cfr. Milosavljevic & Merritt 2001)
Optically faint accretion (Type II QSOs, advection dominated accretion flow) is
negligible for massive SBHs (Yu & Tremaine 2002; but see Elvis, Risaliti &
Zamorani 2002)
 What happens in the lower mass regime (MBH < 108 M) is still to be investigated.
Details depend on the contribution of obscured QSOs, and the exact characterization
of the QSO luminosity function at low redshifts.
The MBH- Relation - Why is it
Interesting?
Falomo, Kotilainen & Treves 2001
Measure SBH masses (30% accuracy!)
 Individual galaxies (e.g. Barth et al. 2002)
 Test accretion processes and unification
schemes
 BL Lacs (Falomo, Kotilainen & Treves
2002; Barth, Ho & Sargent 2002)
 Radio Loud AGN (O’Dowd, Urry &
Scarpa 2002, also Woo & Urry 2002)
 Investigate FRI/FRII dichotomy (Marchesini,
Celotti & Ferrarese 2002, in prep)
SBH Demographics in Local AGNs: the MBHMB
Relation
BLR Size
Virial velocity
Bulge Magnitude
Distances
M/Mbulge
Laor (1998)
Wandel (1999)
McLure & Dunlop (2000)
RL0.5
v = 0.87 FWHM(Hb)
V-band
Bulge/Disk decomp.
H0=80
Rev.Map.
v = 0.87 FWHM(Hb)
B-band
(Simien & de Vaucouleurs)
H0=75
RL0.7
v = 1.55 FWHM(Hb)
I-band
Bulge/disk decomp.
H0=50
0.03%
0.25%
0.6%
BH Demographics in Local AGNs (cont’d)
MBH/Mbulge ~ 0.2%
in agreement with the value determined for local quiescent galaxies (Merritt & Ferrarese 2001a,
Merritt & Ferrarese (2001b, astro-ph/0107134)
Testing Reverberation Mapping With the MBH-
Relation
KPNO/4m - Gemini : On-going program to measure  for
all reverberation mapped galaxies (Ferrarese et al. 2001,
2003)
Malkan, Gorjiam & Tam (1998)
NGC 5548
Testing Reverberation Mapping with the MBH
Relation
 Comparison between mass estimates from resolved kinematics in quiescent
galaxies, and reverberation mapping in Type 1 AGNs shows that reverberation
mapping works!
Ferrarese et al. 2001
Ferrarese et al. 2003
 Future studies targeting the low and high mass end of the MBH relation, as
well as its redshift evolution, will rely on reverberation mapping or secondary
mass estimators calibrated using reverberation mapping.
Part III: Beyond the Bulge: the Dark Side of Galaxies
Recently, it has become commonplace to assume that SBH formation/evolution is driven
exclusively by the dynamically hot stellar component
Kormendy & Gebhardt 2001
However, most self-regulating models of SBH formation link M to the total gravitational mass of
the host galaxy or to the mass of the dark matter halo, rather than to the mass of the bulge (e.g.
Umemura, Loeb & Turner 1993; Loeb & Rasio 1994; Haehenlt, Natarajan & Rees 1998; Silk &
Rees 1998; Cattaneo et al. 1999; Haehnelt & Kauffmann 2000; Adams, Graff & Richstone 2000;
Whyithe & Loeb 2002; Volonteri, Haardt & Madau 2002; Islam,Taylor & Silk 2002).
Is the M relation the fundamental reflection of the processes that lead to the formation of
SBHs? Could M be controlled by the total gravitation mass of the host galaxy instead?
Mass Tracers
Begeman 1987
 Spiral Galaxies: circular velocity of
the cold disk component: 15 objects
with HI or optical rotation curves
extending beyond R25 (e.g. Broeils
1992; Begeman 1987; Olling &
Merrifield 1998; Newton 1980; Kent
1989;Corbelli & Salucci 2000; van
Albada 1980, Krumm & Salpeter 1979;
Bosma 1981)
R25
 Elliptical Galaxies: circular velocity
derived from non-parametric
dynamical modeling: 20 objects
(Kronawitter et al. 2000)
v(circ)/v(max,circ)
Gerhard et al. 2001
r/re
Beyond the Bulge: the vc- Relation
The vc -  Relation
logvc  (0.84  0.09) log  (0.55  0.19);  r2  0.4
M33
N3198
N6503
Ferrarese 2002c, ApJ
The vc -  Relation
 The relation has been recently confirmed, with unchanged slope and scatter using a
new sample of 12 spirals (Baes et al. 2003)
Is the vc- Relation a Tautology?
1. Are vc and  sensitive to the same mass distribution?
vc
c
Is the vc- Relation a Tautology?
2. Is the vc- relation a consequence of dynamical homology?
Casertano & van Gorkom 1991
Is the vc- Relation a Tautology?
3. Is the vc- relation just a reflection of the “disk-halo” conspiracy?
NGC2841
NGC2403
Begeman 1987
Is the vc- Relation a Tautology?
4. Is the vc- relation simply the Tully-Fisher relation in disguise?
Verheijen 2001
Implications of the vc   Relation
 Numerical simulations for the formation of disk galaxies (Steinmetz & Muller 1995) :
Disk rotational
velocity
Bulge velocity
dispersion
Estimating MDM from vc
Bullock et al. 2001
M DM

 3.510 (v /200 km/s) M
12
3

vir

vc
vvir
v  f C  R , R 
r r 
v (R) 
 f (M DM )
 0.75 for M DM 101411 M
0.93for M DM 10 M
vir
vir
vir
s
c



s
The M - MDM Relation
M/MDM ~ 6105
???
M/MDM ~ 106
 M
M
DM

~
0.046
1012 M
108 M§

§
1.57



The MBH - MDM Relation
Wyithe & Loeb 2002
M BH  v c
M BH
 0 f (M halo ,  ,,m ,h,z)
M halo
(LB ,z)  f (,,tQSO )

 Theoretical models for the quasar luminosity
function (Wyithe & Loeb 2002; Hatziminaoglou et
al. 2002)
 QSO emission triggered by galaxy mergers in a
Press-Schechter formalism
 SBH mass proportional to a power  of the halo
circular velocity
Relation Medley
Suggested Readings
 Ferrarese, L. & Merritt, D. 2000
 Gebhardt, K. et al. 2000
 Ferrarese, L. 2001