demography of supermassive black holes: mergers & gravitational waves

Demography of supermassive black holes: mergers & gravitational waves

Françoise Combes

Observatoire de Paris

Monday 9 November

2

Overview

1- Co-evolution of galaxies and Black holes2-Feedback effects?3- Quasars at z~64- MBH growth5-Steps in the BH merging6- Observing binary black holes7- LISA

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Ubiquity of Massive holes in galaxies

The most massive BH Black hole mass scales with bulge mass not

total mass

Some BH at least

Maybe

Giant Ellipticals/S0s Spirals Dwarfs GlobularClusters

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3C31: radio quasars are rare

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Blue: stellar velocities Green: gas velocitiesRed: disks with masers H2O, OH..(Magorrian et al 98, Gebhardt et al 02, Ferrarese &Merritt 01,Tremaine et al 02, Shields et al 02)

Scaling SMBH, M- relation

Mbh = 0.2% Mbulge

Invoked mechanisms

Co-evolution: each time gas is driven to the center to form stars, a fraction fuels the BH

Possible, but through secular evolution/pseudo-bulges & interactions

Delayed co-evolution: Different time-scalesBetter, since it is difficult to find good correlations of AGN and bars, or

with interactions

Self-regulated growthFeedback mechanisms: related to the potential well (bulge mass)

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Co-evolution BH and galaxies

PLE: Pure Luminosity EvolutionLDDE Luminosity-dependent Density Evolution

Ratio 1000since massloss 50%

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BHAR and SFR versus z--SFR

__BHAR

Dotted lines are BHAR shifted by 100 in Number and 20 in Rate

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BHAR and SFR split for intensity

Total is dominated by low-intensities

z=1

Zheng et al 2009

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BHA and SF not in the same objects

fbulge-bh = 650, frecycle=2 1300

z=1

Zheng et al 2009

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Hierarchical formation of BCG

dry mergers since z=150% of stars formed at z=5; mass assembling after z=0.5De Lucia & Blaizot 2007

12

Overview


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Feedback due to Starburst or AGN

Di Matteo et al 2005

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Perseus Clusterexample of AGN

feedback

Salomé et al 2006

Fabian et al 2003

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Overview


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The most distant QSO at z=6.4

Beam 0.3" PdB Age ~ 1 GyrKeck z-bandDjorgovski et al

Fan et al 2003, White et al 2003Mdust ~108Mo (Bertoldi et al 2003)MBH = 1.5 109Mo (Willot et al 2003)No HCN detectedCII, Walter et al 20091kpc scale starburst, 1000Mo/yr/kpc2

CII

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A very early assembly epoch for QSOs The highest redshift quasar currently known

SDSS 1148+3251 at z=6.4 has estimates of the SMBH mass

MBH=2-6 x109 Msun (Willott et al 2003, Barth et al 2003)

As massive as the

largest SMBHs today,

but when the Universe

was <1 Gyr old!

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THE HIGHEST-REDSHIFT QUASARS

Becker et al. (2000)

How do they get a massMbh ~4 109 Mo ?

Seed mass ~4 Mo

20 e-folding times

At Eddington luminositye-folding time40 (/0.1) Myr

Age of the universe at z=6Is 800 Myrs

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Fluctuation generator

Fluctuation amplifier

(Graphics from Gary Hinshaw/WMAP team)

Hot Dense SmoothCool Rarefied

Clumpy

Brief History of the Universe

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BARYONS: need to COOLCOOL First ‘action’ happens in the the

smallest halos with deep smallest halos with deep enough potential wells to allow enough potential wells to allow

this this (at (at z~20-30)

Hierarchical Galaxy Formation:

small scales collapse firstand merge later to form more massive systems

courtesy of M. Kuhlen

First ‘seed’ black holes?

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Overview


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Quasar host

Dark matter Galaxies

Mh= 5 x 1012M

Mh= 51012M M*

= 1011M

SFR = 235 M /yr MBH

= 108M

Quasars end up in cD galaxies at centres of rich galaxy clusters

today

Mh= 2 x 1015M

Descendant

Mh= 21015M

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MBH Growth

• Coalescence dominates dM/dt for z<1

• From Halos to MBHs– Gas physics

• Heating, cooling, star formation

– Accretion

Enoki et al 2005

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BH growthFor simple dimensional relations, we can inferRacc = 0.3 M6/v2

2 pc and dM/dt is the Bondi accretion rate:dM/dt = 4 R2 v = (10-4 Mo/yr) M6

2/v23

since dM/dt ~ M2, then the accretion time is ~ 1/M.for very low BH this takes much larger than the Hubble time.Therefore it requires a large seed, mergers of BH, or very largedensities, like in MW, 107 Mo/pc3

Accretion-dominated growth, tg = tacc. Nice for Seyfert 1For QSO, they reach the Eddington limit, Ledd ~ M,the L ~ dM/dt ~ M2

L/Ledd ~ M, the BH growth slows down when approching Ledd.tedd = M/(dM/dt)edd = 4.5 107 yr (0.1/)equating tacc = tedd, this occurs for Mt = 2 108 Mo v2

3/ (/0.1)

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IMBH: do they exist?

Some theories predict them

Observational constraints: lensing, X-ray sources,galaxy centers, if the BBR extrapolate?

Globular clusters (M15?, G1 in M31)

AGN in dwarf galaxies: NGC 4395 (Filippenko & Ho 2003) MBH = likely 104-105 Mo (Seyf 1, no bulge)Low-ionisation, Lbol/LE = 210-2- 2 10-3

problem of dwarfs: host nuclear star clusters of ~106 Mosolution: only in the Local Group, possible to separate

In M33 < 103Mo, factor 10 below the BBR

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Overview


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Merging steps for binary holes

1. Dynamical friction

2. Binary hardening due to stars

or accretion of gas

3. Gravitational radiation

t a4

t a

Do they merge?

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Steps in a binary BH merger

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DWARF GALAXIES/MINIHALOS

ELLIPTICAL GALAXIES

mass

Vesc

(km

/s)

1000

100

10

109 1013

VVre

coil

reco

il

(km

/s)

(km

/s)

Gravitational rocketbinary center of mass recoil during coalescence due to binary center of mass recoil during coalescence due to

asymmetric emission of GW asymmetric emission of GW (e.g. Fitchett 1983, Favata et al 2004, Blanchet et al 2005, Baker et al 2006)

vvrec rec ≤ 250 km/s≤ 250 km/s

««vvesc esc from today galaxies from today galaxies

≈≈vvesc esc from high-z onesfrom high-z ones

GR SIMULATIONS

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at z >10 more than 80% of merging MBHs can be kicked out of their halo(Volonteri & Rees 2006)

the gravitational rocket effect is a

threat at the highest redshifts, when host halos are small and

have shallow potential wells

Can the merger process start early enough toAllow build-up of supermassive holes? Can the merger process start early enough toAllow build-up of supermassive holes?

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Evidence of recoil?

Komossa et al 2008

The ringdown radiationproduces anti-kickLe Tiec et al 2009

Broad-line region dragged with the MBH

2650 km/s difference with theNarrow-line region

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a1a2

L

L

a1a2

a1a2

L

Low kick velocities (~100 km s-1)High kick velocities (~1000 km s-1)

Recoiling MBHs

Volonteri 2009

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Recoiling MBH

Random distribution of spin moduli

Aligned or anti-aligned spinsspin-orbit isotropy

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Overview


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Predicted Nb binary quasars

Volonteri et al 2009

Not detected in the SDSShigh z, low M, and low L

Today 2 out of 17500 detected

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Are massive black holes rapidly spinning?Radio jets are observed preferentially in E-

galaxiesDue to spin? Spin is modified by BH mergers and Spin is modified by BH mergers and

the coupling with the accretion discthe coupling with the accretion disc

mergers can spin BHs either up or down;

alignment with the disc spins up

In spiral galaxies, more random In spiral galaxies, more random accretion, tidal disruption of stars, accretion, tidal disruption of stars, molecular cloud accretion molecular cloud accretion

BH Spin and host morphology

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spin evolution by BH mergers only

spin evolution by BH mergers AND accretion

X-ray Fe K line

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Mergers of SMBHMerging should take place rapidly enough, to avoid 3 BHand slingshot effect Milosavljevic & Merritt 2001

Wandering simulations

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3C75, Owen et al 1985

OJ287, light curve 100yrs Pietila 98

Roos et al 1993VLBI maps of 1928+738 jetoscillations due to the orbital motions of the BH, period 3.2 yr

42

Overview


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LISA

Will see mergersof 105 –107 Msol

black holes

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Binary BH merger

Centrella Kip Thorne

45Lisa sensitivity to massive black hole binaries