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

1. Co-evolution of Black Holes and Galaxies: Small Scales Issues Andrés Escala Astorquiza DAS, U. de Chile

2. Observational Evidence for Coevolution • 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

3. Small Scale 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?).

4. Massive Black Hole Mergers

5. Mergers of Galaxies & MBHs (Begelman, Blandford & Rees 1980’) Stellar loss-cone depletion by 3-body kicks implies stalling of MBH binary coalescence at sub-parsec separations.

6. MBHs-Disk Interactions • 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)

7. Binary Proto-stars. • 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 …

8. Analytic Estimates • 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

9. Time gap opening/ Time gap closing Δϕ If

10. SPH Simulations for Testing the Criteria (del Valle & Escala 12’)

12. del Valle & Escala (2012) Can’t be explained by Lin & Papaloizou 86’:

13. Comparison of the Literature with del Valle & Escala 12’. Type I Type II

14. Are both types present in the real Universe? Probably YES Type I interaction should be more frequent in wet mergers and Type II in dry ones: Type I Type II

15. MBH accretion, its feedback and possible SF shutoff.

16. AGN Feedback: SF Shutoff? • 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 ++++++:

17. However ….. • 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).

18. Mrk 573 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.

19. If it is not feedback, what can set MBH-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!

20. A personal Candidate: Galactic-Scale Fueling Unavoidable step in the growth of Massive Black Holes and it is indeed a galactic problem! Fueling Flowchart (Wada 2004):

21. Transport Supersonically Turbulent Disk (Final Kpc) 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)

22. THANKS!

23. Motivation: fate of MBHs after Galaxy Mergers 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

24. MBH inclusion in Standard Hierarchical ΛCDM Cosmology Di matteo

25. Gap Opening Condition • 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.

26. Summary I • 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.

27. Star Formation Triggering in Disc Galaxies Part of Fernando Becerra´s Masters Thesis (work currently in progress)

28. KS Law

29. SFR-Mrot relation (Escala 2011)

30. SFR-Σgas/tdyn (Silk)

31. Our work • Explore the possibility of second parameters • Example: Escala (2011)

32. Star Formation Triggering • 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).

34. Summary

35. Differences with terrestrial fluids: • 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.

36. Why Numerical Simulations are so important in Astronomy • 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 ).

37. Astrophysical Fluids • 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.

38. Hydro Methods Used • Eulerian: Adaptive Mesh Refinement (AMR). • Lagrangian: Smooth Particle Hydrodynamics (SPH).

39. Methods: 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

40. SPH Example: Large Scale Struc.

41. Methods: AMR • 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.

42. AMR Example: detonations

43. SPH Simulations using Gadget-2 code.

44. Galaxy Mergers

45. AMR Simulations using ENZO code.