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Cosmological evolution of galaxies and interaction-driven fueling of AGNs

Cosmological evolution of galaxies and interaction-driven fueling of AGNs. N. Menci INAF – Osservatorio Astronomico di Roma. Galaxy Formation in a Cosmological Context. Cosmology Formation and Growth of Dark Matter haloes Their Merging histories Their properties.

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Cosmological evolution of galaxies and interaction-driven fueling of AGNs

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  1. Cosmological evolution of galaxies and interaction-driven fueling of AGNs N. Menci INAF – Osservatorio Astronomico di Roma

  2. Galaxy Formation in a Cosmological Context Cosmology Formation and Growth of Dark Matter haloes Their Merging histories Their properties Collapse of Dark Matter haloes from the primordial density field The growth and merging of virialized DM haloes; Merging of DM haloes, Substrctures Dynamical processes involving galactic-subclumps inside DM haloes: Dynamical friction, Binary aggregations Observable properties of the galaxy population Baryonic Processes Radiative cooling of gas Star formation Supernovae feedback Evolution of stellar Populations Emissions The gas and stellar evolution of galaxies The building of the stellar mass content m*) The evolution star formation rate dm*/dt The evolution of sizes The evolution of the luminosity (UV, B bands → SFR, J, K bands → m*) The colors as indicators of the specific SFR The dependence of the above on the DM mass scale and environment ↔ how the baryonic processes and BH accretion to the cosmological evolution of cosmic structutres Connect Properties of DM haloes To the physical processes involving baryons Growth of SMBHs and AGNs Refueling of cold gas for BH accretion Triggering the gas accretion Accretion rate → Build up of SMBHs The bright phase, the AGN feedback Connect Properties of DM haloes and the baryonic processes To the growth of Supermassive BH and to the AGN activity

  3. time/t0≈0.2 1) Gravitational instability drives the evolution of the Dark Matter density field. 2) Observed power spectrum implies larger perturbation amplitude on smaller scales dc l V. Springel

  4. Red: stars Blue: gas Total mass 3 1012 Mʘ Vrot=270 km/s • Formation time z = 0.75 • Last major merger z=3 • Frame size ~ 200 Kpc Initial (z ~ 4-5) merging events involve small clumps with comparable sizes Disturbed morphology at high z Major merging at z ≈ 3. At later times, merging rate declines Accretion of much smaller clumps F. Governato

  5. Hierarchical Merging of DM haloes and of Substructures Merging Rate of DM haloes Number of Haloes with mass M forming at given time t

  6. Initial (z ~4-6) merging events involve small clumps with comparable sizes Disturbed morphologies at high z Last major merging at z ≈3 for M≈3 1012 Mʘ Last major merging at z ≈ 1 for M≈5 1013 Mʘ At later times, merging rate declines Accretion of much smaller clumps onto the main progenitor z=3 z=1 z=0

  7. The Dynamics of galactic sub-clumps within host Dark Matter haloes A3258 From B.Moore web page

  8. Fdf vH DM substructures loose orbital energy due to the gravitational drag from DM particles in the common halo The larger is the mass of the host halo, the longer is the decay time

  9. N(v,V) = NUMBER OF GALAXIES WITH CIRC. VELOC. v INSIDE A HALO WITH VELOC. V V’ v’ Dynamical Friction v V Binary Merging v” v v’

  10. Frequent halo merging Promptly followed by coalescence of galaxies (effectve dynam. frict). z ~2 (1-3) • - Halo merging rarer • - Longer timescale for • galaxy coalescence by • dynam. friction • Galaxies accumulate • inside host DM haloes

  11. SEMI-ANALYTIC MODELS OF GALAXY FORMATION SEMI-ANALYTIC MODELS OF GALAXY FORMATION SEMI-ANALYTIC MODELS OF GALAXY FORMATION SEMI-ANALYTIC MODELS OF GALAXY FORMATION Kauffman et al. 93 ; Cole et al. 94; Somerville & Primack 00; Cole et al. 00; NM et al. 02; Wu, Fabian, Nulsen 00

  12. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile Gas properties Profiles Cooling Disk Star Form. Rate SNae Feedback Evolution of Stellar Populations

  13. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile Navarro Frenk White 1997 Gas properties Profiles Cooling Disk Star Form. Rate SNae Feedback Evolution of Stellar Populations

  14. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile GAS Gas properties Profiles Cooling Disk DM Star Form. Rate SNae Feedback Evolution of Stellar Populations

  15. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile rcool = radius enclosing the region where tcool≤ tH(z) Gas properties Profiles Cooling Disk Star Form. Rate rcool reset to zero after major merging events (when Mprog < ½ Mmerger) SNae Feedback Evolution of Stellar Populations

  16. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile DM angular momentum J aquired from tidal torques due to surrounding perturbations Assume that, durung collapse, the ratio jgas=Jgas/Jis conserved Gas properties Profiles Cooling Disk Assuming an exponential Surf. Density Profile Assuming centrifugal balance DM Mo, Mao, White 1997 gas

  17. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile with Gas properties Cf. with Shmidt law Profiles Cooling Disk Star Form. Rate SNae Feedback log SFR/Area Evolution of Stellar Populations log GAS Surf. Density

  18. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile Gas properties Profiles Cooling Disk Number of SNae produced per unit stellar mass (depends on IMF) e0≈0. 1 Fract. of SN energy dumped into gas Star Form. Rate SNae Feedback Evolution of Stellar Populations

  19. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile The integrated emission (at wavelength l) from stellar populations is computed after convolving the Spectral Energy Distributions (Fl, Bruzual & Charlot 1993) with the resulting SFR in all the progenitor haloes of the considered galaxy Gas properties Profiles Cooling Disk Star Form. Rate SNae Feedback Evolution of Stellar Populations

  20. Given M, z of DM haloes: Halo properties Average density Virial temperature Virial radius Density profile r (r) Navarro, Frenk, White 1997 Tvir(M) rgas (r) Gas properties Profiles Cooling Disk rd (M, z) vd (M, z) td=rd / vd Mo, Mao White 1998 Star Form. Rate SNae Feedback Evolution of Stellar Populations

  21. 1) Consider a grid of DM halo masses at z=0. Their aboundance is give by PS mass function 2) For each of them construct the merging history 3) At the bottom, assign a baryon mass WbM, initially assumed at virial T: mh=WbM 4) Compute cooled mass mc and the disk size 5) Compute star formation rate mc/t*and hence the amount of formed stars in timestep m*= mc/t*Dt

  22. 6) Computed SN feedback and reheat part of mc to virial temp.

  23. 7) Make 1 timestep upward along the merging tree

  24. 8) In the new halo compute dyn. frict. and aggregation timescales. If galaxies aggregate, merge their gas and stellar content (mh, mc, m*)

  25. 9) Iterate from step 4 (compute cooling in new haloes, star formation, feedback …) 10) For each galaxy, the star formation history in all its progenitor galaxies can be computed at all earlier times and the integrated emission due to stellar populations formed at all earlier times can be computed

  26. Data a) Zwaan et al. 1997 b) Cole + 2001, Bell +, 2003 c) Giallongo et al. 00 d) Mattewson et al. 92 Willick 96 Giovannelli 97 e) Blanton et al. 00 Madgwick et al. 02 Zucca et al.97 f) Steidel et al. 97 Somerville et al. 99-01

  27. The Cosmic Star Formation Rate Z • At high z large • Rapid cooling + gas replenishing due to frequent merging→ large Dmcool • Short Star Form. Timescales 1013 Mʘ 109 Mʘ Z

  28. t1 t2 t3 Large mass halo small mass halo z=0 The star formation histories of the population contained (today) in massive galaxies peaks at higher redshift compared to that of smaller galaxies. Massive galaxies originate from the merging of clumps which have collapsed in biased, high-density regions of the density field, hence at higher redshift.

  29. Low-mass galaxies At high-redshift, cold gas effectively expelled by feedback Suppressed SF at high –z At lower z, haloes grow and feedback becomes less effective Cold gas left available at low-z Star formation still active at low z Smooth SF history High-mass galaxies At high z>2, SF proceeds at extremely high rates Feedback is ineffective in suppressing star formation Rapid gas consumption Cold gas exhausting at z~2 Star formation drops thereafter Local galax.: gas poor, old stars

  30. large mass small mass

  31. Bimodal Color Distribution Bright Red Galaxies Faint BlueGalaxies Baldry et al. 2004

  32. Color Distribution Dependence on luminosity BLUE RED

  33. The cold gas fraction log Number log Number Local galaxies with u-r<1.3 Local galaxies with u-r>2.3 -20.5 < Mr <-19.5

  34. M=109 Mʘ at z=4.5 Mprog=109 Mʘ

  35. Color Distribution: Dependence on the environment

  36. t1 t2 t3 Large mass halo small mass halo z=0 The star formation histories of the population contained (today) in dense environments (groups/clusters) peaks at higher redshift compared to that of smaller galaxies. Galaxies endng up in clusters originate from the merging of clumps which have collapsed in biased, high-density regions of the density field, hence at higher redshift.

  37. Bimodality extends at least up to z ≈ 0.8 z=1.3 Bell et al. 03

  38. 1)The downsizing is naturally predicted in hierarchical models: it originates from the properties of the primordial density field (biasing). 2) The bimodality in the color distribution originates from the interplay between the above biasing properties of the density field and the non-gravitational mass scale defined by the SNae feedback BUT The PARTITION between the faint/Blue and the massive/red galaxies is not correctly reproduced especially at high - z The abundance of massivered galaxies at higher redshift results from a balance between a) the earlier epoch of star formation in their progenitors (due to the denser environment where the formed) + their faster exhaustion of gas b) the lower abundance of massive galaxies at higher z EROS

  39. The Co-evolution of AGNs and its feedback on galaxy evolution The Circumnluclear Starbursts and AGN accretion Triggered by Galaxy Encounters

  40. ‘”tidal forces during encounters cause otherwise stable disks to develop bars, and the gas in such barred disks, subjected to strong gravitational torques, flows toward the central regions “ Part of the available galactic cold gas is detabilized and funnelled toward the centre Mihos & Hernquist 1996 See also Noguchi 1987 Barnes & Hernquist 1991 Cavaliere Vittorini 2000 Gas Angular Momentum (Sanders & Mirabel 96) Governato 05 3/4 feeds circumnuclear starbursts 1/4 feeds central BH QSO Properties Starbursts Properties Interaction rate

  41. Encounter Rate Gas Mass destabilized / Accreted Strongly increases with z Larger r/R ratio Shorter tr ∝(1+z)-1/2 Strongly increases with z larger m’/m ratios Larger vd/V ratio Shorter tr~(1+z)-1/2 Larger cold gas mass Larger f ≥ 0.01 Cavaliere Vittorini 2000 This occurs at a rate and is averaged over all merging partners (m’) in the same group/cluster (with circ. veloc. V) at inpact param. b These quantities + the cold available gas mcold are obtained from the SAM (NM et al. 2002) Bolom. Luminos. BH mass Accretion rate

  42. The Bursts EROs

  43. BURSTS Enhance star formation at z≥4 in massive obsejcts (MZ<25.5) as to match the stellar mass distribution up to z=1.5 MZ≤ 25 NM, Cavaliere, Fontana, Giallongo, Poli, Vittorini 2004

  44. MBH~s4 Cold gas mass ~ s2. Interactions favour large galact. masses → s3. SN feedback disfavour small galact. masses →s3.8

  45. z=2 z=0.5 z=4 z=3 z=1.2 Thenormalizationof the QSO LFs - increases from z=0 to z=2 - decreases for z>2 The rise with z of the normalization is due to the increasing fraction of destabilized cold gas feeding the BH BECAUSE The encounter rate and the hence the accretion rate increases with z Data from Hartwick & Shade 1990, Boyle et al 2000, Fan et al 2001

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