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ACCRETION MODELS FOR BLACK HOLE EVOLUTION
Francesco
ShankarIn collaboration with: D. Weinberg J. Miralda-Escude’ L. Ferrarese A. Cavaliere S. Mathur
CCAPP/OSU BH WORKSHOP 10/2/07
• EMPIRICALLY CONSTRAIN BLACK HOLE EVOLUTION IN A STATISTICAL SENSE
• WE USE: -LOCAL BH MASS FUNCTION -AGN BOL. LUMINOSITY FUNCTION - AGN CLUSTERING
GOAL:
TOOLS:
• For All relations convolve with an “intrinsic” scatter!
How many? How Much?How many? How Much?
Φ(L)→Φ(Lbulge)
MBH - Lbulge
Ф(MBH)
MBH - ()= (L) +L-
The Local Black Hole Mass Function
Systematic and shape uncertainties….
Log MPEAK~8.5
The Bolometric AGN Luminosity Function
Soltan argument
maxmax
min0
2
2
),()1(
)1(z
L
LBoltotal
ACCBH
ACCBolBol
dLzLc
L
dz
dtdzK
MM
cMKLL
Single object
maxmax
min0
2
232
2
),(4
)1()1(
)1()1()(
4),(),(
zS
S
Boltotal
A
LA
L
dSSzSnc
zdzc
K
zD
DzdtcDdV
D
LSdz
dz
dVdLzLdzdSzSn
independent of cosm. par. but very dependent on the ratio Kbol/ε !
SMBH from Merging/Dark Accretion or through Visible Accretion detected in the
AGN luminosity Functions?
Parallel growth of Stars and Black Holes
The ratio <MBH/MSTAR> probably was nearly constantat all times….
Soltan’s constraint: 0.055 < < 0.11
Shankar et al. 2007Shankar & Mathur 2007Shankar, Cavaliere et al. 2007
Varying the Reference Model…
Consequences on BH accretion…dm/dt(z)
dm/dt(MBH) Only works with P(z=6)~0.02 and Super-Edd accretion
Shankar & Ferrarese 2007
Bias in the MBH-n relation??
The Reference Model matches the Clustering of luminous AGNs
BHHALO M
BHBH
M
HALOHALO dMMndMMn )()(
CONCLUSIONS
0.06<<0.11
dm/dt~0.5
More Massive+Sub-EddLess Massive+Edd
Merging
+AGN LF
A Reference Model
CONCLUSIONS
• Normalization --> Radiative Efficiency
0.06<<0.11
• Peak+Clustering --> Edd. ratio of massive BHs dm/dt~0.5 probably
significantly decreasing at z<1
• High End --> Merging events NOT much
The Effect of Merging…
Negligible effect on accretion histories and duty cycles:
Further constraints from AGN BIAS
dMzMnzMPzL
dLzL
dLzLzMLbzb
AGN
L
L
MIN
MIN
),(),(),(
),(
),()],[()(
IDEA: Use the duty-cycles as produced from accretion
-Need to relate BHs to Dark Matter-Further independent test for accretion parameters
Shankar & Weinberg 2007
Varying the accretion rate: L~dm/dtMBH~MH
Remember: L~(dm/dt)MBH~MH
Shankar, Miralda-Escude’ et al. 2007
High Duty cycle at z~6 excluded by the bias…
Successful model:P(z=6)~0.5-1dm/dt~1STAR/Vvir~0.55-0.6
Data from Shen et al.
CONCLUSIONS
•Use of the Local Mass Function and AGN Luminosity Functions to constrain dm/dt and
•Use AGN clustering to constrain further duty-cycles and where Soltan is not sensitive and also probe dependencies on mass/luminosity of dm/dt
FOR THE FUTURE….even worse…
•Towards a multiple dm/dt…build a general P(dm/dt,z,MBH) to compare to the data
•Insert HOD models for AGNs, which could be derived from those of galaxies and apply our average P(M,t)…
Again Radio AGNs..Clustering useful here as well…
Shankar 2007
A sequence of very strong decreasing dm/dt can explain both Clustering and SED…
Changing the Luminosity Function of AGNs…
The Bolometric AGN Luminosity Function
i i
ii aaaxyy2
2321
22 ,....),,;(
BH
A First Estimate of Clustering:The Space Density of AGNs Hosts!
Here I am using an empirical relation calibratedwith a one-to-one approximation…
The Soltan argument can also be applied toRadio AGNs only…
Shankar, Cavaliere et al. 2007
Lradio~fradioLkin
Lkin ~fkinLL~dm/dt c2
Constrain the relation between Luminosity and halo mass…
Independent of duty-cycleIt can give “hints” on the best relation between MBH and MH
Which fits the bias…But then take care to fit the LF!!
MIN
MIN
L
L
dLzL
dLzLzMLbzb
),(
),()],[()(
Shankar & Weinberg 2007
Further constraints from AGN BIAS
MIN
MIN
MIN
MIN
MIN
MH
MH
MAGN
L
L
zMtdMzMnzMtdMzMnzMb
zb
dMzMnzMPz
dLzL
dLzLzMLbzb
),(),(
),(),(),(
)(
),(),()(
),(
),()],[()(
IDEA: Use the duty-cycles as produced from accretion
-Need to relate BHs to Dark Matter-Further independent test for accretion parameters
Shankar & Weinberg 2007
Massive Dark Objects observed in all bulged-galaxies strong link with the host spheroid M/n/
What are MDOs? How and why are they connected with spheroids and DM? What is their role in shaping galaxies?
Marconi & HuntMBHRe2
Log MBH~0.25 dex
VC+DM profile VVIR(zvir=0)(Mvir )1/3
=kVc
+
The XRBG is mostly made of..AGNs!!!
Evolving the black hole Accreted Mass Function….
dM
dL
zMn
zLtMP
mtMPtMtm
tt
MtmtMttM
MlmmcML
jjj
s
),(
),(~),(
),(),()(
)()()(
)(1.02
insert and dm/dt
evolve masses at each timestep
average rate proportionalto “probability”
“probability” given bythe fraction of active BHs
Require initial duty-cycle but at z<3.5 mass functionRequire initial duty-cycle but at z<3.5 mass functionevolves INDEPENDENT of the ansatz…evolves INDEPENDENT of the ansatz…