GALAXIES IN DIFFERENT GALAXIES IN DIFFERENT ENVIRONMENTS: ENVIRONMENTS:

VOIDS TO CLUSTERS: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

GALAXIES IN VOIDSGALAXIES IN VOIDS

M. Hoeft, G. Yepes, S. Gottlober and V. SpringelM. Hoeft, G. Yepes, S. Gottlober and V. Springelastro-ph / 0501394astro-ph / 0501394

Void dwarf dark halos.Void dwarf dark halos.

Gottlöber et al 03Void dwarf galax

Halo Mass function in VoidsHalo Mass function in Voids

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?

VOIDS FROM A 80/h Mpc Box

1024102433 effective particle in void region effective particle in void region MMgas gas = = 5.5106 M MMdark dark = = 3.4107 M Smoothing= 2-0.8 kpcSmoothing= 2-0.8 kpc

10/h Mpc10/h Mpc Simulations done with GADGET2Simulations done with GADGET2Primordial CoolingPrimordial CoolingPhotoionization Photoionization Multiphase mediumMultiphase mediumStar formationStar formationFeedback Feedback

ThermalThermalKinetic (Winds)Kinetic (Winds)

• 20483 effective particles

• RUN with 10243

– Mgas = 1.5106 M

– Mdark= 8.2106 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

(ULTRA)HIGH-RESOLUTION SIMULATIONS OF A VOID IN THE 50/h Mpc Box

10/h Mpc10/h Mpc

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?

Baryon fractionBaryon fraction

Halos belowfew times109 Msun

arebaryon-poor

Characteristicmass scaledepends onredshift

Baryon fract

Characteristic massCharacteristic mass Mc

baryon-rich

baryon-poor

Mc risessignificantlywith z

Halo may startbaryon-richand becomelaterbaryon-poor

Char mass

Tentry

Density temperature phase spaceDensity temperature phase space

Cold modeof galactic gasaccretion:gas creeps alongthe equilibriumline betweenheating and cooling(Keres et al. 04)

Rho T

Max gas temperature

Relate radius to mass

Prediction for Mc

Measurement Mc

Condition for suppression

How to suppress gas condensation?How to suppress gas condensation?How to

Entry temperature versus characteristic massEntry temperature versus characteristic mass

General scaling:factor 1.3

High redshift:empty halos has todevelop

T entry

Mass accretion historyMass accretion historyMass accr hist

Baryon poor small halosBaryon poor small halosMAH, several

total mass baryonic (condensed) mass

Age of starsAge of stars

In small halosstars can onlybe formed at highredshift

Age

Thermal feedbackThermal feedback

Strong wind modelStrong wind model

z=0z=0

Luminosity functionLuminosity function

Color evolutionColor evolution

z=0z=0

z=1z=1

SOME CLUES ABOUT DWARF SOME CLUES ABOUT DWARF GALAXIES IN VOIDSGALAXIES 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,

WORK IN PROGRESS...

DWARF GALAXIES IN GROUPS:

Group five

Baryonfraction againBaryonfraction again

Baryonfraction again

Metallicity enrichment:Metallicity enrichment:Remove baryons by feedback?Remove baryons by feedback?

Dekel+Woo

Feedback

GALAXIES IN CLUSTERSGALAXIES 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.

STAR FORMATION IN STAR FORMATION IN CLUSTERS CLUSTERS

PhotonisationPhotonisationCoolingCoolingMultiphase mediumMultiphase mediumMetallicity Metallicity Wind modelWind model

Springel & Herquist 2003Springel & Herquist 2003

Obtain observational Obtain observational properties of dark halos from properties of dark halos from stars using BC2003 SSP stars using BC2003 SSP models models

Study Study

CDM CLUSTER SIMULATIONSCDM CLUSTER SIMULATIONS

m=0.3; =0.7, h=0.7;

8=0.9

● 80/h Mpc box size. (Initial P(k) for 10243)

● Resample to 1283 particles.

● Identify clusters for

resimulation

GADGET (2-5 kpc)

Z=1; =3 A=1

z=0

LARGE-SCALE SPH SIMULATIONS

m=0.3; =0.7, h=0.7;

8=0.9, b=0.045

500/h Mpc box size. (Initial P(k) for 20483) Runs with up to 5123 particles.

# Halos=4x105 (M>1012 M)

Mdark= 7x1010 M

Identify clusters for

resimulation with 1283

Mass of clusters Mcluster 2.51015 M

Same resolution than

previous simulations 500 h500 h-1-1 Mpc Mpc

Z=1; =3 A=1

z=0

Lx-Tx

TTxx1.91.9

. . MMvirvir > 10 > 1015 15 MM

. 10. 1014 14 < M < Mvirvir < 10 < 101515

.2x10.2x101313 < M < Mvirvir < 10 < 101414

Clusters at 500 Mpc/h

Lx-Tx

. . MMvirvir > 10 > 1015 15 MM

. 10. 1014 14 < M < Mvirvir < 10 < 101515

.2x10.2x101313 < M < Mvirvir < 10 < 101414

TTxx1.91.9

Observations

Clusters at 500 Mpc/h

Lx-Tx

. . MMvirvir > 10 > 1015 15 MM

. 10. 1014 14 < M < Mvirvir < 10 < 101515

.2x10.2x101313 < M < Mvirvir < 10 < 101414

TTxx1.91.9

Observations

Clusters at 500 Mpc/h

Resimulated clusters at 80 Mpc/h

X-ray Temperature Function

LARGE-SCALE SPH SIMULATIONS

The MareNostrum Universe Simulation:

500/h Mpc box size. (Initial P(k) for 20483)

2x10243 particles. # Halos=106 (M>1012 M)

Mdark= 1010 M

Resolution 15 kpc.

500 h500 h-1-1 Mpc Mpc