What did today’s passive galaxies do

in the past

Bianca Poggianti

INAF – Osservatorio Astronomico Padova

Post-starburst galaxies and the intracluster

mediumin the Coma cluster

T. Bridges D. Carter N. Kashikawa Y. Komiyama B. Mobasher S. Okamura B.M. Poggianti M. Yagi

B and R with Japanese mosaic CCD camera on WHT

Spectra for 300 members with WYFFOS/WHT, 6-9 A res., 3600-6600 A

EW(Hdelta) > 3 A

Faint k+a in Coma

Poggianti et al. 2004

Red and blue

Poggianti,Bridges,Komiyama et al. 2004

X-ray from Neumann et al. 2003

all dwarfs

strong, young k+a’s

weak, older k+a’s

K+a galaxies and substructure in Coma

1. The position of faint post-starburst galaxies in Coma relative to X-ray substructure strongly suggestive:

The recent infall of these galaxies onto the cluster and the consequent interaction with the hot ICM were the cause for the abrupt change in their star formation histories

“CAUGHT IN THE ACT”

2. k+a spectrum (=truncation of SF) related to cluster 3. The impact with the ICM can have a strong effect on the

SFH of a galaxy. The effect is FAST. (Vollmer et al. 99,00,01, Quilis et al. 00, Abadi et al. 99)

4. It isn’t easy to pinpoint relation between gal. evol. and substructure, ‘cause it is not easy to identify substructure, i.e. reconstruct the infall history of a cluster

Dressler et al. 1999, Poggianti et al. 1999, Dressler et al. 2004

Post-starburst/post-starforming (k+a) galaxies in the MORPHS sample of 10 clusters at z=0.4-0.5

Observing late star-forming faint galaxies becoming “dwarf ellipticals”

About 10% of the dwarf cluster population

Caldwell et al.’s works

Tran et al. 2003

Comparison Coma - clusters at z=0.4-0.5

Downsizing effect:

k+a’s: a luminous phenomenon at z=0.5 and a faint one at z=0?

probably reflecting a change in the SF properties of the infalling galaxies

evolution of the MAXIMUM LUMINOSITY of k+a galaxies in clusters – another evidence for downsizing

going to lower redshifts, the maximum luminosity/mass of galaxies with significant SF activity progressively decreases – active star formation in low mass galaxies seems to be (on average) more protracted than in massive galaxies

Well-known dependence on galaxy mass/luminosity: the more massive, the oldest

both in clusters – Smail et al. 1998 Bower et al. 1999 Halliday 1999 Kajisawa et al. 2000 Nakata et al. 2001 Kodama & Bower 2001 Poggianti et al. 2001a,b (ages and metallicities as a fn. of the galaxy luminosity) De Propris et al. 2003 De Lucia et al. 2004 Kodama et al. 2004

and in the field – Cowie et al. 1996, Kauffmann et al. 2003, Bell et al. 2003

The questions

1. Was the SB induced by the impact with the ICM?

2. Could it be strangulation?

5. k+a’s in the field at low z are dwarf galaxies too?

6. Is this inconsistent with hierarchical modeling+semi-analytics?

7. What is the origin of the downsizing effect?

Possibly

No

SF in low mass galaxies more protracted on average than in massive galaxies: most likely “intrinsic”, not environmental

It depends on SFE assumptions

Giant galaxies known

3. Is the origin of k+a galaxies in distant clusters the same as of k+a’s in Coma? ?

4. Are there k+a dwarf galaxies in distant clusters?

? Ongoing VLT project

S. White ( MPA-Garching, D )A. Aragón-Salamanca ( Nottingham, UK )R. Bender ( Munich, D )P. Best ( ROE, Scotland )M. Bremer ( Bristol, UK )S. Charlot ( MPA, D & IAP, F )D. Clowe ( Bonn, D)J. Dalcanton ( U.Washington, USA )B. Fort ( IAP, F )P. Jablonka ( OPM, F )G. Kauffmann ( MPA, D )Y. Mellier ( IAP, F )R. Pello ( OMP, F )B. Poggianti ( Padova, I )

H. Rottgering ( Leiden, NL )P. Schneider ( Bonn, D )D. Zaritsky ( U. Arizona, USA )M. Dantel ( OPM, F )G. De Lucia ( MPA, D )V. Desai ( U. Washington, USA )C. Halliday ( Padova, I )B. Milvang-Jensen ( MPE, D )S. Poirier ( OPM, F )G. Rudnick ( MPA, D )R. Saglia ( Munich, D )L. Simard ( U. Victoria, C )

The ESO Distant Cluster Survey

Study evolution of clusters and cluster galaxies in a uniform imaging and spectroscopic database over

½ of the Hubble time

EDisCS – ESO Distant Cluster Survey

10 + 10 cluster fields selected from the Las Campanas Distant Cluster Survey (Gonzales et al. 2001):

• Deep imaging: VRIJK at z~0.8, BVIK at z~0.5 (11n FORS2 + 20n SOFI)

• Spectroscopy: at least 4 FORS2 masks at long exposure to get spectra to I~23 (z~0.8) or 22 (z~0.5) (22n FORS2)

• HST/ACS imaging for 10 most distant clusters (80 orbits)

• WFI 3-color imaging for all 20 fields (84hr WFI)

ESO LP allocation: 36n VLT/FORS2 + 20n NTT/SOFI

CL1202.4-1224

z=0.42

EDisCS Imaging10 “high-z” fields in VRIJK, 10 “low-z” fields in BVIK

CL1232.3-1250z=0.54

CL1037.5-1243

z=0.58

CL1054.4-1245

z=0.75

CL1354.1-1231

z=0.76

EDisCS – ESO Distant Cluster Survey

10 + 10 cluster fields selected from the Las Campanas Distant Cluster Survey (Gonzales et al. 2001):

• Deep imaging: VRIJK at z~0.8, BVIK at z~0.5 (11n FORS2 + 20n SOFI)

• Spectroscopy: at least 4 FORS2 masks at long exposure to get spectra to I~23 (z~0.8) or 22 (z~0.5) (22n FORS2)

• HST/ACS imaging for 10 most distant clusters (80 orbits)

• WFI 3-color imaging for all 20 fields (84hr WFI)

ESO LP allocation: 36n VLT/FORS2 + 20n NTT/SOFI

Morphology HST

CL1037.5-1243

z=0.58

CL1216.4-1201

z=0.79

EDisCS – ESO Distant Cluster Survey

10 + 10 cluster fields selected from the Las Campanas Distant Cluster Survey (Gonzales et al. 2001):

• Deep imaging: VRIJK at z~0.8, BVIK at z~0.5 (11n FORS2 + 20n SOFI)

• Spectroscopy: at least 4 FORS2 masks at long exposure to get spectra to I~23 (z~0.8) or 22 (z~0.5) (22n FORS2)

• HST/ACS imaging for 10 most distant clusters (80 orbits)

• WFI 3-color imaging for all 20 fields (84hr WFI)

ESO LP allocation: 36n VLT/FORS2 + 20n NTT/SOFI

Halliday et al. 2004

A&A in press

(astro-ph 0408071)

Halliday et al. 2004 --- cl1216 at z=0.8

Halliday et al. 2004 (astro-ph 0408071)

Halliday et al. 2004 (astro-ph 0408071)

Halliday et al. 2004 (astro-ph 0408071)

De Lucia et al. 2004, ApJL 610, L77

De Lucia et al. 2004 ApJ Letter

Data from Terlevich et al. (2001)

Smail et al. 1998; Kajisawa et al. 2000, Nakata et al. 2001, Kodama et al. 2004

De Lucia et al. 2004 ApJL

-- Defining as “faint” galaxies 0.4 < L/L* < 0.1 (5σ detection limit), the luminous-to-faint ratio on the red sequence is 0.34±0.06 in Coma and 0.81±0.18 in EDisCS

-- The effect is seen also in the single-cluster distributions, despite of the variety of cluster properties: such a deficit may be a universal phenomenon in clusters at these redshifts

A deficiency of red galaxies at faint magnitudes compared to Coma

-- A synchronous formation of stars in all red sequence galaxies is ruled out, and the comparison with Coma quantifies the effect as a function of galaxy magnitude

-- A large fraction of the red faint galaxies has moved onto the red sequence relatively recently, having their SF presumably ended at z<0.8

Stay tuned on EDisCS……..

Stellar population analysis of cluster galaxy spectra (see Halliday’s poster)

Tully-Fisher relation of cluster and field galaxies up to z~0.8 (see Milvang-Jensen’s poster)

Metallicity-luminosity relation of star-forming galaxies (see Moustakas’s poster)

Stay tuned on EDisCS…soon to come Evolution of galaxy masses and IR phot. (Aragon-Salamanca et al.)

Weak lensing mass reconstructions (Clowe et al.)

HST galaxy morphologies in clusters at 0.8 – Evolution of galaxy Hubble types, of merger rates and properties, and of the morphology-density relation (Desai et al.)

Differences between group and cluster galaxies up to z~0.8 (Halliday et al.)

The spectroscopy of the remaining 14 clusters (Milvang-Jensen et al.)

Star formation and evolutionary histories in clusters from z=0.8 (Poggianti et al.)

The Fundamental-Plane of early-type galaxies (Saglia et al.)

Bulge-to-disk decompositions and early-type galaxy fractions (Simard et al.)

Presentation of the survey and of the optical photometry (White et al.)………………………

Halliday et al. 2004

Tran et al. 2003 (see Tran’s talk)

EDisCS is an international project involving 26 astronomers from 7 countries. The original proposal was submitted by the following group of co-investigators :

 S. White ( MPA-Garching, D ) - Principal Investigator -

A. Aragón-Salamanca ( Nottingham, UK ) R. Bender ( Munich, D )

P. Best ( ROE, UK )M. Bremer ( Bristol, UK )

S. Charlot ( MPA, D & IAP, F )D. Clowe ( Bonn, D)

J. Dalcanton ( U.Washington, USA )B. Fort ( IAP, F )

P. Jablonka ( OPM, F )G. Kauffmann ( MPA, D )

Y. Mellier ( IAP, F )R. Pello ( OMP, F )

B. Poggianti ( Padova, I )H. Rottgering ( Leiden, NL )

P. Schneider ( Bonn, D )D. Zaritsky ( U. Arizona, USA )

 Others actively involved in the project currently include: 

M. Dantel ( OPM, F )G. De Lucia ( MPA, D )

V. Desai ( U. Washington, USA )C. Halliday ( Padova, I )

B. Milvang-Jensen ( MPE, D )S. Poirier ( OPM, F )

G. Rudnick ( MPA, D )R. Saglia ( Munich, D )

L. Simard (  U. Victoria, C )  

cl1054-11 z=0.70 EDISCS - Desai et al. in preparation

Ground based and HST images

Cl1037.5-1243Cl1037 - Desai et al. in prep.