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 holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

3 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/S0sSpiralsDwarfsGlobular Clusters

4 3C31: radio quasars are rare

5 Blue: stellar velocities Green: gas velocities Red: disks with masers H 2 O, OH.. (Magorrian et al 98, Gebhardt et al 02, Ferrarese &Merritt 01, Tremaine et al 02, Shields et al 02) Scaling SMBH, M-  relation M bh = 0.2% M bulge

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-scales Better, since it is difficult to find good correlations of AGN and bars, or with interactions  Self-regulated growth Feedback mechanisms: related to the potential well (bulge mass)

7 Co-evolution BH and galaxies PLE: Pure Luminosity Evolution LDDE Luminosity-dependent Density Evolution Ratio 1000 since mass loss 50%

8 BHAR and SFR versus z --SFR __ BHAR Dotted lines are BHAR shifted by 100 in Number and 20 in Rate

9 BHAR and SFR split for intensity Total is dominated by low-intensities z=1 Zheng et al 2009

10 BHA and SF not in the same objects fbulge-bh = 650, frecycle=2  1300 z=1 Zheng et al 2009

11 Hierarchical formation of BCG dry mergers since z=1 50% of stars formed at z=5; mass assembling after z=0.5 De Lucia & Blaizot 2007

12 Overview 1- Co-evolution of galaxies and Black holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

13 Feedback due to Starburst or AGN Di Matteo et al 2005

14 Perseus Cluster example of AGN feedback Salomé et al 2006 Fabian et al 2003

15 Overview 1- Co-evolution of galaxies and Black holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

16 The most distant QSO at z=6.4 Beam 0.3" PdB Age ~ 1 Gyr Keck z-band Djorgovski et al Fan et al 2003, White et al 2003 M dust ~10 8 Mo (Bertoldi et al 2003) M BH = Mo (Willot et al 2003) No HCN detected CII, Walter et al kpc scale starburst, 1000Mo/yr/kpc 2 CII

17 A very early assembly epoch for QSOs The highest redshift quasar currently known SDSS at z=6.4 has estimates of the SMBH mass M BH =2-6 x10 9 M sun (Willott et al 2003, Barth et al 2003) As massive as the largest SMBHs today, but when the Universe was <1 Gyr old!

18 THE HIGHEST-REDSHIFT QUASARS Becker et al. (2000) How do they get a mass M bh ~ Mo ? Seed mass ~4 Mo  20 e-folding times At Eddington luminosity e-folding time 40 (  /0.1) Myr Age of the universe at z=6 Is 800 Myrs

19 Fluctuation generator Fluctuation amplifier (Graphics from Gary Hinshaw/WMAP team) Hot Dense Smooth Cool Rarefied Clumpy Brief History of the Universe

20 COOL BARYONS: need to COOL the smallest halos with deep enough potential wells to allow this First ‘action’ happens in the smallest halos with deep enough potential wells to allow this (at (at z~20-30) Hierarchical Galaxy Formation: small scales collapse first and merge later to form more massive systems courtesy of M. Kuhlen First ‘seed’ black holes?

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22 Overview 1- Co-evolution of galaxies and Black holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

23 Quasar host Dark matter Galaxies M h = 5 x M  M h = 5  M  M * = M  SFR = 235 M  /yr M BH = 10 8 M  Quasars end up in cD galaxies at centres of rich galaxy clusters today M h = 2 x M  Descendant M h = 2  M 

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25 MBH Growth Coalescence dominates dM/dt for z<1 From Halos to MBHs –Gas physics Heating, cooling, star formation –Accretion Enoki et al 2005

26 BH growth For simple dimensional relations, we can infer R acc = 0.3 M 6 /v 2 2 pc and dM/dt is the Bondi accretion rate: dM/dt = 4  R 2 v  = (10 -4 Mo/yr) M 6 2 /v 2 3  since dM/dt ~ M 2, 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 large densities, like in MW, 10 7 Mo/pc 3 Accretion-dominated growth, t g = t acc. Nice for Seyfert 1 For QSO, they reach the Eddington limit, L edd ~ M, the L ~ dM/dt ~ M 2 L/L edd ~ M, the BH growth slows down when approching L edd. t edd = M/(dM/dt) edd = yr (0.1/  ) equating t acc = t edd, this occurs for M t = Mo v 2 3 /  (  /0.1)

27 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) M BH = likely Mo (Seyf 1, no bulge) Low-ionisation, L bol /L E = problem of dwarfs: host nuclear star clusters of ~10 6 Mo solution: only in the Local Group, possible to separate In M33 < 10 3 Mo, factor 10 below the BBR

28 Overview 1- Co-evolution of galaxies and Black holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

29 Merging steps for binary holes 1. Dynamical friction 2. Binary hardening due to stars or accretion of gas 3. Gravitational radiation t  a 4 t  a Do they merge?

30 Steps in a binary BH merger

31 DWARF GALAXIES/ MINIHALOS ELLIPTICAL GALAXIES mass V esc (km/s) V recoil (km/s) Gravitational rocket binary center of mass recoil during coalescence due to asymmetric emission of GW (e.g. Fitchett 1983, Favata et al 2004, Blanchet et al 2005, Baker et al 2006) v rec ≤ 250 km/s « v esc from today galaxies ≈ v esc from high-z ones GR SIMULATIONS

32 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 to Allow build-up of supermassive holes? Can the merger process start early enough to Allow build-up of supermassive holes?

33 Evidence of recoil? Komossa et al 2008 The ringdown radiation produces anti-kick Le Tiec et al 2009 Broad-line region dragged with the MBH 2650 km/s difference with the Narrow-line region

34 a1a1 a2a2 L L a1a1 a2a2 a1a1 a2a2 L Low kick velocities (~100 km s -1 ) High kick velocities (~1000 km s -1 ) Recoiling MBHs Volonteri 2009

35 Recoiling MBH Random distribution of spin moduli Aligned or anti-aligned spins spin-orbit isotropy

36 Overview 1- Co-evolution of galaxies and Black holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

37 Predicted Nb binary quasars Volonteri et al 2009 Not detected in the SDSS high z, low M, and low L Today 2 out of detected

38 Are massive black holes rapidly spinning? Radio jets are observed preferentially in E-galaxies Due to spin? Spin is modified by BH mergers and the coupling with the accretion disc Spin is modified by BH mergers and the coupling with the accretion disc mergers can spin BHs either up or down; alignment with the disc spins up  In spiral galaxies, more random accretion, tidal disruption of stars, molecular cloud accretion BH Spin and host morphology

39 spin evolution by BH mergers only spin evolution by BH mergers AND accretion X-ray Fe K  line

40 Mergers of SMBH Merging should take place rapidly enough, to avoid 3 BH and slingshot effect Milosavljevic & Merritt 2001 Wandering simulations

41 3C75, Owen et al 1985 OJ287, light curve 100yrs Pietila 98 Roos et al 1993 VLBI maps of jet oscillations due to the orbital motions of the BH, period 3.2 yr

42 Overview 1- Co-evolution of galaxies and Black holes 2-Feedback effects? 3- Quasars at z~6 4- MBH growth 5-Steps in the BH merging 6- Observing binary black holes 7- LISA

43 LISA Will see mergers of 10 5 –10 7 Msol black holes

44 Binary BH merger Centrella Kip Thorne

45 Lisa sensitivity to massive black hole binaries