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Coeval Evolution of Galaxies and Supermassive Black Holes : Cosmological Simulations. J. A. de Freitas Pacheco Charline Filloux Fabrice Durier Matias Montesino Collaborators J. Silk – Oxford T.P. Idiart – USP Miguel Preto - Heidelberg. The Facts.
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Coeval Evolution of Galaxies and Supermassive Black Holes : Cosmological Simulations J. A. de Freitas Pacheco Charline Filloux Fabrice Durier Matias Montesino Collaborators J. Silk – Oxford T.P. Idiart – USP Miguel Preto - Heidelberg
Observational evidences for the existence of massive BH in the core of galaxies Sagittarius A* - galactic centre DMO in M87, M84 and NGC4261 Ghez et al. 1998
Black holes and galaxies • Strong correlations are observed between the black hole mass and : • Stellar velocity dispersion: • Stellar bulge mass : • Stellar bulge luminosity : Tremaine et al. 2002 ; Gebhardt et al.2000 Haring and Rix, 2004 Marconi and Hunt, 2003 Dark halo mass : Baes et al. 2003 Co-evolution of SMBH and galaxies
Lower Mass Limits • * Lower limits • - negative searches for intermediate • mass black holes • - upper limits for M33 (3103 M ) and • NGC 205 (3.8104 M ) • indirect evidence for IMBH in NLSeyf1 • (8104 - 8106 M )
Origin of Seeds (*) Intermediate mass black holes (103-104 M) formed in : a) the collapse of primordial gas clouds (Haehnelt & Rees 1993) b) the core collapse of star clusters formed in starburts (Shapiro 2004) (*) Collapse of primordial massive stars (100-300 M) formed in high density peaks of the primordial fluctuation spectrum
Cosmological simulations Difficulties Advantages Two extreme scales : Galaxies interactions : several kpc Black hole physics : sub-pc scales • follow up of seeds • gas dynamics & merger tree • follow up of the star formation history v=0.7 m=0.3 bh2= 0.0224 h=0.70 8=0.9
The Code GADGET-II Springel 2005 Introduction of BH seeds at potential minima (z=15) Star formation (conversion of gas into tars) Hydrodynamics (SPH) Gravitation (tree code) DARK MATTER GAS STARS SMBH SMBH coalescences during galaxy mergers Supernovae (type Iaand II) AGN activity (feedback) Ionisation, heating and radiative cooling BH Growth (« disk » and HLB mode) Galactic winds Metal enrichment
Code Parameters Energy injected by supernovae Weight for the blast energy per particle ’’turbulent’’ diffusion efficiency Accretion mode spherical (Bondi – Hoyle) ’’disk’’ gravitational energy AGN feedback rotational energy Jet length 100 - 400 kpc Jet angle
Detection of Structures • Structure determination FoF SubFind Davis et al, 1985 ; Huchra and Geller, 1982 Springel et al, 2001
Dynamical Properties of Simulated Galaxies ’’Red’’ galaxies (U-V)>1.1 and (B-V)>0.8 ’’Blue’’ galaxies otherwise Faber-Jackson & Tully-Fisher relations Angular momenta of blue & red galaxies
Properties of Simulated Galaxies Grey zone – SDSS data from Gallazzi et al. 2005
The mass function at z=0 • All simulations give similar results, with BHMF slightly overestimated for M● >107M • BH seeds of 100 M: evolution of massive • pop III stars 192/160 :resolution disk/kerr : AGN feedback fromaccretion /rotation S : withhigherSNIaefficiency
Evolution of the Black hole mass density Black hole mass density at z=0 Estimates :ρ●= 2 - 9 x 105 M.Mpc-3 Chokshi and Turner 1992 ; Salucci et al., 1999 ; Aller and Richstone, 2002 ; Marconi et al, 2004, … Assuming bolometric luminosity proportional to the accretion rate 192/160 :resolution disk/kerr : AGN feedback fromaccretion /rotation S : withhigherSNIaefficiency
The M● - σ relation Cygnus A, NGC 5252, NGC 3115 and NGC 4594 192disk simulation • Good agreement, except for the four galaxies having black holes apparently too massive.
The M● - Mhalo relation 192disk simulation • Mhaloisdirectlyextractedfrom simulations. • Good agreement with Baes et al, 2003.
Some problems: no SMBH at z ~ 6! • No supermassive black holes at z=6 hierarchical growth • No super-Eddington accretion rates are observed (resolution effect?)
Coalescence of two massive BHs • Four regimes can be recognized: • adiabatic – sequence of quasi-circular geodesic orbits • transition – near the innermost stable orbit • plunge – merger of the two horizons • iv) ring-down – normal modes of the distorted black hole tThre Total energy radiated under the form of GW in the adiabatic phase Frequency near the ’’last stable orbit’’ Maximum mean frequencies – adiabatic regime
Expected contribution to the background Expected flux at the observer’s frame total merger rate per comoving volume and With Fraction of mergers with a parameter occurring at z Equivalent density parameter
Ring-down contribution to the background Expected flux Equivalent density parameter Duty cycle
Ring-down background(shot-noise – D <<1) Spin data: Daly 2009 Shot-noise
I. Conclusions • Cosmological simulations are the best tool to study the coeval evolution of galaxies and their central black holes • Properties of gas, galaxies and the growth of supermassive black holes depend strongly on feedback mechanisms, in particular the downsizing effect • Simulated galaxies have adequate mass profiles, satisfying the Faber-Jackson (red galaxies), the Tully-Fisher (blue galaxies) and the mass-metallicity relation
II. Conclusions • Seeds ( ~ 100 M) originated from the evolution of zero metallicity massive stars are able to explain SMBH, by growing through accretion and coalescences • Simulated SMBH satisfy the mass distribution observed in the local universe as well as the evolution of the BH mass density, the M● vs and the M● vs Mhalo relations • Gravitational waves can put strong constraints on the coalescence history of seeds • However, difficulties exist such: a) no SMBH are seen at z ~ 6 b) density of massive galaxies are overestimated c) simulated <Fe> and Mg2 indices still do not reproduce adequately the observations d) blue galaxies do not have enough angular momentum