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GALAXIES IN DIFFERENT ENVIRONMENTS: VOIDS TO CLUSTERS:

GALAXIES IN DIFFERENT ENVIRONMENTS: VOIDS TO CLUSTERS:. Simulations will require to model full physics: Cooling, heating, star formation feedbacks… Large dynamical range: resolving galaxies in different density environments. Important problems to address:

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GALAXIES IN DIFFERENT ENVIRONMENTS: VOIDS TO CLUSTERS:

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  1. GALAXIES IN DIFFERENT ENVIRONMENTS: VOIDS TO CLUSTERS: • Simulations will require to model full physics: • Cooling, heating, star formation feedbacks… • Large dynamical range: resolving galaxies in different density environments. • Important problems to address: • Excess of small scale structure in CDM models: making small halos invisible?. • Hubble sequence (formation of disks) • Interactions galaxy -ICM

  2. GALAXIES IN VOIDS M. Hoeft, G. Yepes, S. Gottlober and V. Springel astro-ph / 0501394

  3. Void dwarf galax Void dwarf dark halos. Gottlöber et al 03

  4. Halo Mass function in Voids

  5. The missing dwarf galaxy problemin VOIDS • No galaxies brighter than Mb=-15 found. • What happens with baryons of small halos in voids? • Are they visible but faint?. Magnitude, colors. (Red Dwarfs) • Are they just baryonless dark halos? • What are the physical mechanism • Gas evaporation by UV photoionization • Supernova feedback (e.g Dekel & Silk) • What is the typical halo mass for this to happen?

  6. VOIDS FROM A 80/h Mpc Box 10/h Mpc Simulations done with GADGET2 Primordial Cooling Photoionization Multiphase medium Star formation Feedback Thermal Kinetic (Winds) 10243 effective particle in void region Mgas = 5.5106 M Mdark = 3.4107 M Smoothing= 2-0.8 kpc

  7. (ULTRA)HIGH-RESOLUTION SIMULATIONS OF A VOID IN THE 50/h Mpc Box 20483 effective particles RUN with 10243 Mgas = 1.5106 M Mdark= 8.2106 M Spatial smoothing= 0.5 kpc Different feedback params. Same void was resimulated with full resolution 20483 Mgas  2 105 M Mdark 106 M Spatial smoothing= 0.5 kpc 10/h Mpc

  8. The missing dwarf galaxy problemin VOIDS • No galaxies brighter than Mb=-15 found. • What happens with baryons of small halos in voids? • Are they visible but faint?. Magnitude, colors. (Red Dwarfs) • Are they just baryonless dark halos? • What are the physical mechanism • Gas evaporation by UV photoionization • Supernova feedback (e.g Dekel & Silk) • What is the typical halo mass for this to happen?

  9. Baryon fract Baryon fraction Halos below few times 109 Msun are baryon-poor Characteristic mass scale depends on redshift

  10. Char mass Characteristic massMc Mc rises significantly with z Halo may start baryon-rich and become later baryon-poor baryon-rich baryon-poor

  11. Rho T Tentry Density temperature phase space Cold mode of galactic gas accretion: gas creeps along the equilibrium line between heating and cooling (Keres et al. 04)

  12. How to Condition for suppression How to suppress gas condensation? Max gas temperature Relate radius to mass Prediction for Mc Measurement Mc

  13. T entry Entry temperature versus characteristic mass General scaling: factor 1.3 High redshift: empty halos has to develop

  14. Mass accr hist Mass accretion history

  15. MAH, several Baryon poor small halos total mass baryonic (condensed) mass

  16. Age Age of stars In small halos stars can only be formed at high redshift

  17. Luminosity function Thermal feedback Strong wind model z=0

  18. Color evolution z=1 z=0

  19. SOME CLUES ABOUT DWARF GALAXIES IN VOIDS • Halos below Mlim~ 7x109 M (vc~27 km/s) are photo-evaporated and have almost no baryon content, either cold gas or stars. This mass scale decreases with redshift. Very small dependence of UV flux. • UV-heating not able to suppress small galaxies: Problem for semianalitical models to explain substructure in the Local Group. • Thermal feedback does not play a significant role in keeping gas out of halos. • Kinetic feedback (winds) can be very efficient in inhibitting star-formation: Z agreement, redder colors,

  20. WORK IN PROGRESS...

  21. DWARF GALAXIES IN GROUPS:

  22. Group five

  23. Baryonfraction again Baryonfraction again

  24. Feedback Metallicity enrichment: Remove baryons by feedback? Dekel+Woo

  25. GALAXIES IN CLUSTERS • Entropy generation from galactic feedback. • Scaling relations and non-adiabatic physics. • Understanding Intracluster light. • Effect of central Cd-galaxy on ICM radial profiles. • Cold fronts and cold flows. • How many galaxies survive in the cluster environment? • Very demanding simulations: • E.g. Cluster 6 simulated with 4.5 million particles within 3 virial radius took more than 680,000 timesteps to finished.

  26. STAR FORMATION IN CLUSTERS • Photonisation • Cooling • Multiphase medium • Metallicity • Wind model • Springel & Herquist 2003 • Obtain observational properties of dark halos from stars using BC2003 SSP models • Study

  27. LCDM CLUSTER SIMULATIONS • Wm=0.3; WL=0.7, h=0.7; s8=0.9 • 80/h Mpc box size. (Initial P(k) for 10243) • Resample to 1283 particles. • Identify clusters for resimulation GADGET (2-5 kpc)

  28. Z=1; a=3 A=1 z=0

  29. LARGE-SCALE SPH SIMULATIONS • Wm=0.3; WL=0.7, h=0.7; s8=0.9, Wb=0.045 • 500/h Mpc box size. (Initial P(k) for 20483) • Runs with up to 5123 particles. • # Halos=4x105 (M>1012 M) • Mdark= 7x1010M • Identify clusters for resimulation with 1283 • Mass of clusters • Mcluster  2.51015 M • Same resolution than previous simulations 500 h-1 Mpc

  30. Z=1; a=3 A=1 z=0

  31. Lx-Tx Clusters at 500 Mpc/h Tx1.9 . Mvir > 1015 M . 1014 < Mvir < 1015 .2x1013 < Mvir < 1014

  32. Lx-Tx Clusters at 500 Mpc/h Tx1.9 . Mvir > 1015 M . 1014 < Mvir < 1015 .2x1013 < Mvir < 1014 Observations

  33. Lx-Tx Clusters at 500 Mpc/h Tx1.9 Resimulated clusters at 80 Mpc/h . Mvir > 1015 M . 1014 < Mvir < 1015 .2x1013 < Mvir < 1014 Observations

  34. X-ray Temperature Function

  35. LARGE-SCALE SPH SIMULATIONS • The MareNostrum UniverseSimulation: • 500/h Mpc box size. (Initial P(k) for 20483) • 2x10243 particles. • # Halos=106 (M>1012 M) • Mdark= 1010M • Resolution 15 kpc. 500 h-1 Mpc

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