the colour-magnitude relation in galaxy clusters from z~0.8 to z=0

Gabriella De Lucia, November Gabriella De Lucia, November 7,Berkeley7,Berkeley

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The colour-magnitude relation The colour-magnitude relation in galaxy clusters in galaxy clusters from z~0.8 to z=0from z~0.8 to z=0

Gabriella De LuciaGabriella De LuciaMax-Planck Institut für AstrophysikMax-Planck Institut für Astrophysik


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An old result

Visvanathan & Sandage (1977)

De Propris et al. (1998)

5 mag!!!

Coma

The CMR - some factsThe CMR - some facts

Mei et al. 2006


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This model may be too naiveThis model may be too naive a galaxy does not have a single well defined progenitor at a galaxy does not have a single well defined progenitor at each redshift each redshift (De Lucia & Blaizot 2006)

a it neglects the infall of new galaxiesa it neglects the infall of new galaxies

The CMR - the conjectures #1The CMR - the conjectures #1

A monolithic collapse occuring at high redshiftA monolithic collapse occuring at high redshift slope naturally arises taking into account SNe winds slope naturally arises taking into account SNe winds (Arimoto & Yoshii 1987)

a tight CM up to high redshift consistent with a passivea tight CM up to high redshift consistent with a passive evolution evolution (Kodama et al. 1998)

Gladders et al. 1998

obs. data

De Lucia & Blaizot 2006


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The CMR - the conjectures #2The CMR - the conjectures #2

A hierarchical merger modelA hierarchical merger model slope arises because more massive Es form from theslope arises because more massive Es form from the mergers of more massive discs mergers of more massive discs (Kauffmann & Charlot 1998)

a tight CM up to high redshift - the results are robusta tight CM up to high redshift - the results are robustagainst halo-to-halo scatter against halo-to-halo scatter (De Lucia, PhD thesis)

Mean progenitor mass normalised to final mass


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A truncation in the A truncation in the CMR in high CMR in high

redshift clustersredshift clusters


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deep optical photometry from VLT (14 nights) deep optical photometry from VLT (14 nights)

Completed – White et al. 2005Completed – White et al. 2005

near-IR photometry from NTT (20 nights)near-IR photometry from NTT (20 nights)

Completed - Aragon-Salamanca et al. in preparationCompleted - Aragon-Salamanca et al. in preparation

multi-object spectroscopy with FORS2 on VLT (25 nights)multi-object spectroscopy with FORS2 on VLT (25 nights)

Completed - Halliday+ 2006; Milvang-Jensen+ in prepCompleted - Halliday+ 2006; Milvang-Jensen+ in prep

80 orbits of HST to image 10 high-z clusters!!!80 orbits of HST to image 10 high-z clusters!!!

Completed - Desai et al. in preparationCompleted - Desai et al. in preparation

WFI R (120m), V, I (60m) WFI R (120m), V, I (60m)

CompletedCompleted

A detailed follow-up of 20 clusters from LCDCS (Gonzalez et al. A detailed follow-up of 20 clusters from LCDCS (Gonzalez et al. 2001)2001)

10 clusters at z 10 clusters at z 0.5 and 10 clusters at z 0.5 and 10 clusters at z 0.8 0.8

The The EEso so DisDistant tant CCluster luster SSurveyurvey


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A wide range of masses and A wide range of masses and structural propertiesstructural properties

White et al. 2005

Some Some EDisCS EDisCS clustersclusters


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Some Some EDisCS EDisCS CMRsCMRs

De Lucia et al. 2006, astro-ph/0610373


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The CMR - passive evolutionThe CMR - passive evolution

redshift

zero

-poin

t


The location of the The location of the CMR requires high CMR requires high redshifts of redshifts of formation (z~3) formation (z~3) and the slope is and the slope is consistent with a consistent with a correlation betweel correlation betweel luminosity and luminosity and metal contentmetal content


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# o

f gala

xie

s z = 0.45 z = 0.57

z = 0.75

# o

f gala

xie

s

MI(obs)

MI(obs)

MV(rest)MV(rest)MV(rest)

The build-up of the CMR #1The build-up of the CMR #1


l/f = 0.48 +/- 0.08l/f = 0.53 +/- 0.09

0.71 +/- 0.10 0.86 +/- 0.13

0.89 +/- 0.14 0.95 +/- 0.14

redshift

nlu

m/

nfa

int


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redshift

nlu

m/n

fain

t



the blue galaxies observed in distant galaxy clusters provide the logical progenitors of faint red galaxies at z=0


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# o

f gala

xie

s

# o

f gala

xie

s

MV(rest)

MI(obs)

sigma < 600 km/s

sigma > 600 km/s


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nlu

m/n

fain

t

redshift

sigma > 600 km/s

sigma < 600 km/s


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redshift

redshift

nlum/nfaint


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Semi-analytic Semi-analytic modelsmodels


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galaxy galaxy formatioformatio

nn

Cooling (metallicity,structure, conductivity)

Star formation (threshold, efficiency, initial mass function)

Dust (formation, distribution, heating and cooling)

Galaxy interactions (morphological transformations, induced star formation)

Winds (IGM heating, IGM enrichment)

Stellar evolution (spectro-photometric evolution, yields,feedback)

AGN (BH growth, feedback)


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Mathis H. et al., 2002

CDM CDM

The SAM - the hybrid modelsThe SAM - the hybrid models


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Halo galaxy

Central galaxy

Satellite galaxy

Springel et al. (2001)

De Lucia De Lucia etet al., 2004 al., 2004

The SAM - the hybrid modelsThe SAM - the hybrid models


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feedback

star formation

recycling

Hot Gas

Cold Gas cooling

Ejected Gas

Stars

re-incorporation

De Lucia, Kauffmann & White, 2004De Lucia, Kauffmann & White, 2004

- AGN heating- AGN heating

Croton et al. 2006Croton et al. 2006

The SAMs - the (simplified) physicsThe SAMs - the (simplified) physics


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The evolution of the CM relation in SAM models

ComaSingle burst zf=3Exp. tau = 1

The build-up of the CMR in SAMsThe build-up of the CMR in SAMsDe Lucia et al. in preparation

U-V

U-VU-V

U-V

U-V

MV MV MV

MV MV


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Very little build-up of the red-sequence!

De Lucia et al. in preparation

The build-up of the CMR in SAMsThe build-up of the CMR in SAMsV

-I V-I

V-I V-I

nlu

m/n

fain

t

MVMI MI

MIMI redshift

l/f = 0.31z = 0.0

l/f = 0.37z = 0.32

l/f = 0.38z = 0.41

l/f = 0.45z = 0.62

l/f = 0.47z = 0.76

U-V


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u - r

Quantitatively the CM bimodality is not well reproduced

oTail of blue bright objects

o Transition region not well populated

o Excess of faint red satellites

The colour-magnitude bimodalityThe colour-magnitude bimodality

u - r

Mr = -

22.75

Mr = -21.25

Mr = -19.75 Mr = -18.25

Baldry et al. 2004

in preparation

fract

ion

fract

ion


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The D4000 distributionThe D4000 distribution

fract

ion

fract

ion

D4000 D4000 D4000

Same problems in the D4000 distribution

in preparation


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redshift

cluster ellipticals

field ellipticals

Lookback time (Gyr)

Mstar = 1012 Msun

Mstar = 109 Msun

The star formation historyThe star formation history

Most massive elliptical galaxies also the shortest formation timescales

De Lucia et al. 2006


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1010M 1011M 1012M

cluster

field

Lookback time (Gyr)De Lucia et al. 2006

The star formation historyThe star formation history


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50 % stars in a single object

80 %

redshift

Formation and assemblyFormation and assembly

50 % stars formed

80 %

Fract

ion

of

gala

xie

s

redshift De Lucia et al. 2006


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De Lucia & Blaizot, De Lucia & Blaizot, astro-ph/0606519astro-ph/0606519

””Assembly vs formation”Assembly vs formation”historyhistory

125 BCGs selected 125 BCGs selected @z=0@z=0

Formation and assembly of BCGsFormation and assembly of BCGs


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Mstar [M h-1]

Eff

ect

ive #

of

Eff

ect

ive #

of p

rog

en

itors

pro

gen

itors

Neff = 1/2 Neff = 1/2 Mfinal/<Mform>Mfinal/<Mform>

No disk instability

Disk instability

In the monolithicIn the monolithicapproximation: Neff=1approximation: Neff=1

The ellipticals progenitors numberThe ellipticals progenitors number

De Lucia et al. 2006


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Log[Mstar]Log[Mstar]

The age and metallicity dependenceThe age and metallicity dependenceB

- V

B -

V

Log[Mstar]Log[Mstar]

z=0.00z=0.00

z=0.00z=0.00

z=0.28z=0.28

z=0.28z=0.28

z=0.51z=0.51

z=0.51z=0.51

z=0.76z=0.76

z=0.76z=0.76

z=1.08z=1.08

z=1.08z=1.08

Zsta

r/ZZ

star/Z

Age (G

yr)

Age (G

yr)

De Lucia et al. in preparation


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ConclusionsConclusions

Indication for a truncation of the colour-magnitude relation at high redshift Dependence on environment not clear SAMs do reproduce “qualitatively” the observed down-sizing A clear difference between “assembly” and “formation” time SAMs do not reproduce “quantitatively” the colour bimodality

the colour-magnitude relation in galaxy clusters from z~0.8 to z=0

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