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A Physical Model for Co-evolution of QSOs and of their Spheroidal Hosts Gianfranco De Zotti

A Physical Model for Co-evolution of QSOs and of their Spheroidal Hosts Gianfranco De Zotti with: Francesco Shankar, Andrea Lapi, Luigi Danese, Gian Luigi Granato, Michele Cirasuolo, Paolo Salucci, Laura Silva. Observational connections between galaxy and BH properties.

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A Physical Model for Co-evolution of QSOs and of their Spheroidal Hosts Gianfranco De Zotti

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  1. A Physical Model forCo-evolution ofQSOs and of their Spheroidal Hosts Gianfranco De Zotti with: Francesco Shankar, Andrea Lapi, Luigi Danese, Gian Luigi Granato, Michele Cirasuolo, Paolo Salucci, Laura Silva

  2. Observational connections between galaxy and BH properties • BH are generally connected with the (generally old) bulge stellar population not with the younger disk population (Kormendy & Gebhardt 2001; Kormendy & Ho 2000; Salucci et al. 2000) • Tight relationship between BH mass and stellar velocity dispersion (Tremaine et al. 2002):

  3. M_BH is also well correlated with the mass in stars(Häring & Rix 2004): • Further relationships can be derived comparing the Galactic Halo Mass Function with the Stellar and BH mass functions or with the velocity dispersion function (Shankar et al. 2005): where the GHMF is derived from the halo mass function (Sheth & Tormen 2002), adding the contribution of sub-halos (Vale & Ostriker 2004) and subtracting that of groups and clusters (Martinez et al. 2002)

  4. Examples: • Mass in stars vs halo mass Different behaviour above and below Mh~2.5 1011 Msun !

  5. The -Vvir relation and the Velocity Dispersion Function(Loeb & Peebles 2003; Cirasuolo et al 2005) The -Vvir relation is a key ingredient to connect theoretical predictions with observations Vvir is controlled by dynamics of halos, while  feels the effect of dissipative baryon setting From observational point of view: (L) + (L- relation) () Loeb & Peebles (2003) From theoretical point of view: n(Mvir, zvir) + v2vir(vvir) GMvir/rvir PS+ST

  6. The -Vvir relation and the Velocity Dispersion Function  = 0.57 ± 0.05 Vvir Dynamical attractor (Gao et al. 2004)? Major mergers rarer in sufficiently massive halos?

  7. A simplified feedback model(Shankar et al. 2005; Granato et al. 2004) • The gas, heated at virial temperature, cools down and falls towards the central star-forming region at a rate where and fcosm= b/DM0.19

  8. Dezotti:  is the effective efficiency of cold gas removal by SN feedback • The time derivative of the cold, star-forming gas mass is where R0.3 for a Salpeter IMF and

  9. so that the efficiency of gas removal by SN feedback is Setting

  10. The differential equation can be solved to give: where  = 1– R +  and At the present time

  11. For and 1-Rconst. so that consistent with the data For small masses, so that with a much flatter slope than inferred from the data (effect of reheating?)

  12. BH growth Radiation drag dissipates the angular momentum of gas clouds allowing them to infall toward the central BH at a rate (Kawakatu & Umemura 2002): The final BH mass is then:

  13. After Granato et al. (2004): since and, for , Thus, for large masses, and

  14. For small masses (« 1) consistent with the steepening indicated by the data: whence

  15. Dezotti: f_c: covering factor of AGN-driven winds N_22: gas column densityi n 10^22 cm^-2 f_h: fraction of AGN kinetic power transferred to the gas AGN energy transferred to the gas • Kinetic luminosity (Granato et al. 2004), erg/s • For Eddington limited accretion: with for  = 0.1, so that for and e.g.:

  16. Scheme of our semi analytical model at high z Halos form, gas is shock heated to virial T Gas cools, collapse and forms stars directly, in small halos SNae quench SF, in big ones nothing prevents a huge burst of SF ('1000 M¯/yr over 0.5 Gyr), SMGs phase SF promotes the growth of a SMBH, powering high z QSO. QSO activity expels the ISM, terminating SF and its own growth. QSO phase (almost) passive evolution of stellar population follows. ERO phase with dormant SMBH

  17. INGREDIENTS of physical model (zvir>1.5, logM vir>11.5) • formation of dark matter halos, starting from primordial density fluctuations. PS (ST) formalism is used • shock-heating & radiative cooling of gas in DM halos • collapse of cold gas & star formation from cold gas • chemical and energetic feedback from stars (SNae) • formation of low angular momentum reservoir with arate  SFR (radiation drag Umemura 2001) • Growth of SMBH, limited by Eddington, viscosity, fuel availability • Feed-back on cold gas due to increasing QSO activity • luminosity evolution of stellar populations • absorption of starlight by dust & re-emission in IR+sub-mm (our GRASIL, Silva et al 1998)

  18. Example at zvir=4 Evolution of galaxy Evolution of SMBH Mvir=2e12 accretion rate SFR Mvir=1e13 Evolution faster in more massive halos Granato et al 2004

  19. Chemical abundances (in stars) at z=0 as a function of M(halo) Granato et al 2004

  20. K band local Luminosity function of spheroids Data: Huang et al 2003 Kochanek et al 2001 Granato et al 2004

  21. Silva et al 2005 <—— Cimatti et al. (2002) <—— Somerville et al. (2004) Star forming Passive

  22. z = 0.5 z =1.3 z = 0.9 z = 1.8 Fontana et al 2004: galaxy stellar mass function in K20 sample Standard SAMs Granato et al 2004 Standard SAMs underproduce massive galaxy, by a fraction increasing with z

  23. ABC scenario naturally reproduces SMGs statistic SCUBA 850 m data model MAMBO 1200 m

  24. The central BH dispersion interpreted as different virialization epochs Steepening at low ? (due to greater effectiveness of SNae and lower )  = 0.57 ± 0.05 Vvir Tighter MBH-M*?

  25. MBH vs Mh (1)

  26. MBH vs Mh (2)

  27. Mass function of local SMBH observations model

  28. THE PRE-QSO PHASE The build up by accretion of the SMBH, promoted by SF and before the bright optical QSO phase, gives rise to a mild AGN activity in sub-mm galaxies detectable in hard-X. Indeed ~75% of >4 mJy SCUBA sources host an X-ray AGN with intrinsicLX[0.5-8]1043-1044erg s-1 (Alexander et al 03,04,05) dM/dt(BH)>0.02 M¯/yr ) L(0.5-8)>1E43 erg/s dM/dt(BH)>0.2 M¯/yr ) L(0.5-8)>1E44 erg/s dM/dt(BH)>1 M¯/yr )L(0.5-8)>5E44 erg/s

  29. QSO luminosity functions (work in progress)

  30. + slow decrease of Lbol/ LEdd with z, from 4 at >6 to 0.8 at <2

  31. Optical LF (1) z=1.5 tvis=3 107 yr

  32. Optical LF (2) z=3.1 tvis=4 107 yr

  33. Optical LF (3) z=4.5 tvis=4 107 yr

  34. Optical LF (4) z=6 tvis=4 107 yr

  35. Evolution of the optical luminosity function

  36. Our model is not affected by this problem! (and without tuning of parameters) QSOs with L>31047 erg/s Models in which a fraction of the halo mass is accreted at each major merger, when normalized to produce the density of QSO at z»6, tend to overproduce the density at lower z (Bromley et al. 2004).

  37. ..the cosmic accretion rate is in agreement with results of optical surveys (e.g. Fan et al. 2003)

  38. Unabsorbed X-ray (0.5-8 keV) light curve of QSOszvir=4 Mh=2.5 1012 Msun X-ray binaries  AGN activity Mh=2.5 1013 Msun

  39. Hard X-ray luminosity function (1)  Ueda et al. (2003)  Barger et al. (2005) z=1.5 tvis= 108 yr

  40. Hard X-ray luminosity function (2)  La Franca et al. (2005)  Ueda et al. (2003)  Barger et al. (2005) z=1.5 tvis= 3 108 yr

  41. Hard X-ray luminosity function (3)  La Franca et al. (2005)  Ueda et al. (2003)  Barger et al. (2005) z=2.5 tvis= 108 yr

  42. QSOs Bright Ellipticals r0 6.4 Mpc/h (Grazian et al. 2004) SCUBA galaxies EROs Z > 1.5 Z  1.2 Z  0 r0= 8-11 Mpc/h (Norberg et al. 2003) r0 5-12 Mpc/h (Daddi et al. 2003) r0= 83 Mpc/h (Smail et al. 2003) Clustering • SCUBA - QSO - EROs are subsequent stages inside large DM halos  highly and similarly clustered.

  43. Conclusions (1) • A simple physical recipe accounts for the observed galaxy & AGN “downsizing” in the framework of the standard hierarchical clustering scenario • Key role played by SN and AGN feedback; the relative importance varies with Mh • Faster and earlier evolution for more massive objects • Data consistent with basic galaxy and AGN properties in large halos (Mh  2.5 1011 Msun) established at the virialization epoch; subsequent merging and baryon dissipation have apparently little effect

  44. Conclusions (2) • The model successfully reproduces: • the observational relationships between Mh, Mbulge, and MBH • the the galaxy velocity dispersion function and the fundamental plane relationships (Cirasuolo et al. 2005) • the local BH mass function (Shankar et al. 2005a) • the galaxy and QSO epoch-dependent luminosity functions in different bands

  45. Conclusions (3) • The model yields: • an extended dust-obscured phase of BH growth • a fast increase of the MBH/Mstar ratio in the pre-optical QSO phase (cf. Borys et al. 2005) • mildly differential evolution of the LF • optical visibility time 1 e-folding time • hard X-ray visibility time  3–4 e-folding times • higher luminosity sources are less absorbed (cf. La Franca et al. 2005) • high metallicity and -enhancement associated to high-z quasars; metallicity increases with luminosity (cf. Roberto Maiolino’s talk)

  46. Conclusions (4) • faster high-z decline of QSO luminosity density, compared with SFR • MBH –Mstar and MBH –  relations established at high z in the optically bright QSO phase and unchanged during the subsequent passive evolution (ERO) phase • a prolonged “starving” phase of massive BHs (low radiative/accretion efficiency, ADAF, C-DAF, ADIOS ...) • Additional ingredients required for less massive halos, which evolve more slowly, are mostly associated with disk galaxies, and are found in lower density environments

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