Co-evolution of Black Holes and Galaxies: Small Scales Issues
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Co-evolution of Black Holes and Galaxies: Small Scales Issues. Andrés Escala Astorquiza DAS, U. de Chile. Observational Evidence for Coevolution. M BH - σ (Ferrarese & Merrit/Gebhardt et al. 2000), M BH -M bulge (Marconi & Hunt 2003) relations.

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Co evolution of black holes and galaxies small scales issues

Co-evolution of Black Holes and Galaxies: Small Scales Issues

Andrés Escala Astorquiza

DAS, U. de Chile


Co evolution of black holes and galaxies small scales issues

Observational Evidence for Coevolution Issues

  • MBH-σ (Ferrarese & Merrit/Gebhardt et al. 2000), MBH-Mbulge (Marconi & Hunt 2003) relations.

  • Co-evolution of cosmic SFR (Madau plot) and AGN activity.

  • AGN Heating needed for Galaxy Luminosity Function (Croton et al. 06’).

MBHs must be included in Standard Hierarchical Galaxy Formation within ΛCDM Cosmology


Co evolution of black holes and galaxies small scales issues

Small Scale Issues: Issues

  • Two basic unsolved issues that needs to be understood for a comprehensive scenario for MBH-Galaxy co-evolution are:

  • MBHs Mergers vs Last Parsec Stalling (->GW Recoil vs Three body problem).

  • MBH growth and its feedback on the environment (SF shutoff?).



Co evolution of black holes and galaxies small scales issues

Mergers of Galaxies & MBHs Issues

(Begelman, Blandford & Rees 1980’)

Stellar loss-cone depletion by 3-body kicks implies stalling of MBH binary coalescence at sub-parsec separations.


Co evolution of black holes and galaxies small scales issues

MBHs-Disk Interactions Issues

  • Gaseous disks are main candidates for extracting angular momentum from MBH binaries and drive the final coalescence.

  • Simulations in the literature of binary-disk interactions can be divided in 2 groups:

Escala et al. 04,05

Dotti et al. 09

Artymowicz & Lubow 94

Shi, Krolig et al. 12

tmerge ~ torb(Type I)

tmerge ~ 1000 torb(Type II)


Co evolution of black holes and galaxies small scales issues

Binary Proto-stars. Issues

  • Different stages in the process of formation of binary stars shows different interactions with the gaseous envelopes.

  • This will not only affect their final separation but also in their final masses since accretion also varies dramatically in both cases.

  • Relevant to investigate when starts the type II stage.

Artymowicz & Lubow (1994) & more…

Boss (1984) & more …


Co evolution of black holes and galaxies small scales issues

Analytic Estimates Issues

  • Analytical estimates for a Gap Opening Condition can be computed by comparing the timescales for closing (~∆R2/νturb) and opening (~∆L/T) a Gap.

  • Computed for torques from a Global Non-axisymmetric Density Enhancement instead from the Resonances that appears in the linear theory (not applicable for q≈1, only for q<<1).

  • Gives a criteria that can be expressed on 2 dimensionless quantities of the binary-disk system: h/rbin Mgas(<rbin)/Mbin




Co evolution of black holes and galaxies small scales issues

del Valle & Escala (2012) 12’)

Can’t be explained by Lin & Papaloizou 86’:



Co evolution of black holes and galaxies small scales issues

Are both types present in the real Universe? Probably YES 12’.

Type I interaction should be more frequent in wet mergers and Type II in dry ones:

Type I

Type II



Co evolution of black holes and galaxies small scales issues

AGN Feedback: SF Shutoff? 12’.

  • Proposed by several authors, based on simple analytical estimates of BH growth/feedback (e.g. Silk and Rees 98, King 03, Wyithe & Loeb 03, Begelman & Nath 05).

  • DiMatteo et al (2005); Hopkins et al ++++++:


Co evolution of black holes and galaxies small scales issues

However ….. 12’.

  • Resolution ≈ 100 RBHinf (all BH-physics totally unresolved).

  • These simulations have almost the same assumptions that simple analytical estimates (-> do not test them).

  • A better approach is to perform smaller scale simulations that test these hypothesis.

  • An example: hypothesis of Eddington Limited growth can be exceed thru Photon Trapping (Begelman 78), Super-Eddington Atmospheres due to unstable photon-bubbles (Begelman 02; Krumholz et al 05, 09).


Co evolution of black holes and galaxies small scales issues

Mrk 573 12’.

Measuring AGN Feedback:

  • Several ongoing attempts to quantify AGN feedback in both wind & jet modes (Krongold et al. 07,10; Rupke & Veilleux 11’; Harrison et al. 12’) .

  • However, total momentum and energy observed in the outflow is still lower than required (~1/10) .

  • Energy & momentum comes in the form of ionized gas  Canthis component transfer its momentum into heating the molecular ISM and stopping SF.


Co evolution of black holes and galaxies small scales issues

If it is not feedback, what can set M 12’.BH-σ/MBH-MBulgerelations?

  • Two Possibilties:

  • No physical link between BH and Galaxies (Jahnke & Macciò 11’), relations are just a N vs N plot.

  • Such link exists and we need to look for alternatives. Any galactic problem relevant in controlling MBH growth will work.

Implicit assumption of huge number of MBH mergers!


Co evolution of black holes and galaxies small scales issues

A personal Candidate: Galactic-Scale Fueling 12’.

Unavoidable step in the growth of Massive Black Holes and it is indeed a galactic problem!

Fueling Flowchart (Wada 2004):


Co evolution of black holes and galaxies small scales issues

Transport Supersonically Turbulent Disk (Final Kpc) 12’.

BH ~ vrot 3 (Escala 06’,07’)

G

Mass transport in turbulent disk (assuming a power-law inertial range):

 KS Law BH α Bulge

E(k)~k-5/3

E(k)~k-3

Becerra, M.Sc. 12’

Levine et al (2008)


Co evolution of black holes and galaxies small scales issues

THANKS! 12’.


Co evolution of black holes and galaxies small scales issues

Motivation: fate of MBHs after Galaxy Mergers 12’.

Galaxy mergers are common events in the universe.

Each galaxy with a sizeable bulge is expected to have a MBH.

What is the fate of the BHs? Will also Coalesce?

NGC 6240


Co evolution of black holes and galaxies small scales issues

MBH inclusion in Standard Hierarchical 12’.ΛCDM Cosmology

Di matteo


Co evolution of black holes and galaxies small scales issues

Gap Opening Condition 12’.

  • The migration timescales predicts completely different behaviours (in the two cases) in terms of an eventual coalescence.

  • Crucial to predict whether a Gap will be opened or not and apply it for different scenarios for binary MBHs/Protostars growth.

  • Since Type I disks are generally thicker and more massive than Type II ones, M and H will be parameters to explore.


Co evolution of black holes and galaxies small scales issues

Summary I 12’.

  • We have studied under which conditions the interaction of a disk with a binary will open a gap.

  • We successfully test our analytical expectations against full 3-D hydrodynamic simulations.

  • We are now in the position to predict under which scenarios we expect an efficient MBH merging.

  • Also in a position to study when starts the type II stage in binary proto-stars.


Co evolution of black holes and galaxies small scales issues

Star Formation Triggering in Disc Galaxies 12’.

Part of Fernando Becerra´s Masters Thesis (work currently in progress)


Co evolution of black holes and galaxies small scales issues

KS Law 12’.


Co evolution of black holes and galaxies small scales issues

SFR-M 12’.rot relation (Escala 2011)


Co evolution of black holes and galaxies small scales issues

SFR-Σ 12’.gas/tdyn (Silk)


Co evolution of black holes and galaxies small scales issues

Our work 12’.

  • Explore the possibility of second parameters

  • Example: Escala (2011)


Co evolution of black holes and galaxies small scales issues

Star Formation Triggering 12’.

  • Aim: Study galactic-scale triggering of star formation.

  • In particular the role of Mrot (maximum mass scale not stabilized by rotation)

  • Compare different star formation laws: Kennicutt Law vs SFR-Mrot relation (Escala 2011).


Co evolution of black holes and galaxies small scales issues

Summary 12’.


Co evolution of black holes and galaxies small scales issues

Differences with terrestrial fluids: 12’.

  • Nontrivial Flows: on the Earth generated by solid bodies. In space also by gravitational forces, radiation field and explosions.

  • Astrophysical fluids are frequently partially ionized. Thus, electromagnetic forces can play a role in the macroscopic dynamics.


Co evolution of black holes and galaxies small scales issues

Why Numerical Simulations are so important in Astronomy 12’.

  • Most problems requires a large dynamic range (4, 5, 6 and more orders of magnitude).

  • A broad variety of physical processes involved (gravity, hydro, radiation, B, etc) in complex geometries (full 3-d).

  • HPC needed! (Software & Hardware solutions ).


Co evolution of black holes and galaxies small scales issues

Astrophysical Fluids 12’.

  • Basic Ingredients:

  • Gravity: always.

  • Hydrodynamics: gas, stars only when collisions are not negligible.

  • Many More: Radiation Fields, G.R. corrections, Chemical/Nuclear Reactions, etc. -> generally included as sub-grid physics.


Co evolution of black holes and galaxies small scales issues

Hydro Methods Used 12’.

  • Eulerian: Adaptive Mesh Refinement (AMR).

  • Lagrangian: Smooth Particle Hydrodynamics (SPH).


Co evolution of black holes and galaxies small scales issues

Methods 12’.: SPH

  • The fluid its sampled and represented by particles smoothed by a kernel W.

  • Allows any function to be expressed in terms of its values at a set of disordered points, i.e.:

  • hj is the variable smoothing length, adjusted to keep the number of neighbors N constant.

N

ρ(r) = Σ mj W(r-rj;hj)

j=1

adaptive spatial resolution



Co evolution of black holes and galaxies small scales issues

Methods: AMR 12’.

  • Grid-based Technique.

  • Uses a criteria for automatic increase of the resolution.

  • Criterias can be chosen to guarantee resolve: density contrast, jeans length , shocks, etc.