P.I. 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 ) J. Varela ( Padova, I) + B. Vulcani (Padova, I) + J. Fritz (Padova, I) The ESO Distant Cluster Survey (EDisCS) Study evolution of cluster galaxies and clusters in 20 fields with clusters at z=0.4 – “ITALIANI”

Parent Sample: LasCampanasDistantClusterSurvey Gonzalez et al Uniform selection in the optical (130 square deg) Select bright candidates with z(est)~0.5 and z(est)~0.8 from the Las Campanas Distant Cluster Survey Image each field in 2 bands for 20min with FORS2 (3n FORS) Select best cluster fields for deep imaging

Deep imaging: VRIJK at z~0.8, BVIJK at z~0.5 (11n FORS2/VLT + 20n SOFI/NTT) HST/ACS imaging for 10 most distant clusters (80 orbits) Spectroscopy: at least 4 FORS2 masks at long exposure to get spectra to I~23 (z~0.8) or 22 (z~0.5) (25n FORS2) + follow-ups (XMM, MIPS/Spitzer, Halpha imaging, wide-field spectroscopy, GALEX …): MIPS+IRAC data for all fields, some WF WFI/2.2m RVI imaging for all 20 fields (84hr WFI) The ESO Distant Cluster Survey (EDisCS) 20 fields with clusters at z= ESO LP allocation: 36n VLT/FORS2 + 20n NTT/SOFI

CL z=0.42 EDisCS Imaging CL z=0.54 CL z=0.58 CL z=0.75 CL z=0.76

Morphology  ACS/HST CL z=0.58 CL z=0.79

Deep imaging: VRIJK at z~0.8, BVIJK at z~0.5 (11n FORS2/VLT + 20n SOFI/NTT) HST/ACS mosaic imaging for 10 most distant clusters (80 orbits) Spectroscopy: at least 4 FORS2 masks at long exposure to get spectra to I~23 (z~0.8) or 22 (z~0.5) (25n FORS2) + follow-ups (XMM, MIPS/Spitzer, Halpha imaging, wide-field spectroscopy, GALEX…): MIPS+IRAC data for all fields, some WF WFI/2.2m RVI imaging for all 20 fields (84hr WFI) The ESO Distant Cluster Survey (EDisCS) 20 fields with clusters at z= ESO LP allocation: 36n VLT/FORS2 + 20n NTT/SOFI

Spectroscopy 25 nights of FORS2 MXU spectroscopy  average of 35 members/cluster z’s and emission lines to I~23 (over ~3.5mag) Line strength to I~22.5 ’s to I~21.5

Deep imaging: VRIJK at z~0.8, BVIJK at z~0.5 (11n FORS2/VLT + 20n SOFI/NTT) HST/ACS mosaic imaging for 10 most distant clusters (80 orbits) Spectroscopy: at least 4 FORS2 masks at long exposure to get spectra to I~23 (z~0.8) or 22 (z~0.5) (25n FORS2) + follow-ups (XMM, MIPS/Spitzer, Halpha imaging, wide-field spectroscopy, GALEX…): MIPS+IRAC data for all fields, some WF WFI/2.2m RVI imaging for all 20 fields (84hr WFI)+ IMACS/Magellan LR spectra… The ESO Distant Cluster Survey (EDisCS) 20 fields with clusters at z= ESO LP allocation: 36n VLT/FORS2 + 20n NTT/SOFI

Wide range of cluster masses Milvang-Jensen et al  Wider range of masses than previous surveys  EDisCS structures progenitors of “typical” clusters today  Allows to study clusters, groups and field on homogeneous data

19 clusters, 10 groups (8+ members), poor groups and 120 usable field galaxies Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl1138a Cl1037a Cl Cl Cl Cl Cl Cl1354a Cl1227a Cl Cl1301a Cl1103a Cl Cl1040b Cl1103b Cl105411a Cl Cl105412a Cl1040a Cl others Redshift, sigma, N of members

24 refereed papers published or submitted, + some ongoing studies.…. see Poggianti et al. June 2009 Messenger RED GALAXIES V-I I magnitudeDe Lucia et al Well-defined relation between colour and luminosity (red sequence) for clusters up to z=1.5, of galaxies whose SF terminated well before the epoch we observe them Not all today’s red sequence galaxies have been red and passive since high- z Downsizing of the red sequence: most massive/luminous galaxies stopped forming stars, and were on the red sequence at an earlier epoch than less massive ones

0.0 redshift 0.8 Number ratio of red luminous-to-faint galaxies De Lucia et al Deficit of faint, red galaxies in distant clusters compared to nearby clusters. Rudnick et al Also from spectral line indices analysis (Sanchez-Blazquez et al. 2009) BCG stell. pops formed at z 2, no significant evolution in mass since z=1 (whiley et al. 2008) Build-up of the faint end of the red galaxy LF – Field has more faint red galaxies than clusters at z=0.7, but fewer at z=0.5

On the way to the red sequence: evolution of the % of SF-ing galaxies EDisCS z = Sloan z = Fraction of members with OII within R200 Velocity dispersion Poggianti et al. 2006

Desai et al. (2007) (Dressler et al. 1997, Fasano et al. 2000, Postman et al. 2005, Smith et al – but also Andreon et al. 1998, Holden et al. 2009) MORPHOLOGICAL EVOLUTION IN CLUSTERS: from spiral to S0 GALAXIES Elliptical % S0 % Spiral+Irr % Also Simard et al for evolution of EDisCS early-type fraction E + S0 %

Desai et al. (2007) Morphological fractions vs redshift Most of the morphological evolution in luminous galaxies has occurred since z=0.5, during the last 5 Gyrs.

WINGS + EDisCS Poggianti et al. 2009b ApJ Letter Evolution of the morphological fractions as a function of velocity dispersion AGAIN, THE STRONGEST EVOLUTION BETWEEN z=1 AND TODAY APPEARS TO HAPPEN IN GALAXIES IN LOW-MASS CLUSTERS

 The fraction of passive galaxies observed at high-z is about the fraction of galaxies that were already in groups (M > 3 X 10^12) at z=2.5  The fraction of passive galaxies observed at low-z is about the fraction of galaxies that have spent at least the last 3 Gyr (since z=0.3) in clusters (M > 10^14) Poggianti et al. 2006

Poggianti et al Morphology-density relation

Based on OII line Poggianti et al AnticorrelatedUncorrelated Star-forming fraction Local density Mean(EW) of OII galaxies Local density STAR FORMATION-LOCAL DENSITY RELATION Z=0 (red, SDSS clusters) Z= (black, EDisCS) The EDisCS star formation-density relation qualitatively resembles that observed at low-z: higher density regions have fewer star-forming galaxies, and the average EW(OII) of star-forming galaxies is independent of local density. Thus the SF in star-forming galaxies not affected by local environment? No….

Poggianti et al All galaxies (black) SFing galaxies (blue) Clusters + groups at z~ Average SFR and sSFR vs density SFR and SSFR in star-forming galaxies peaks at intermediate densities at high-z? In summary: The fraction of star-forming galaxies and the SFR in star-forming galaxies, at least in clusters depend on local density.

Vulcani et al. submitted THE SFR-MASS RELATION IN CLUSTERS, GROUPS AND FIELD Z= 0.4 – 0.6Z = 0.6 – 0.8 Lower median SFR in cluster star-forming galaxies of a given mass then in the field -- Groups like the field?? Average SFR in star-forming galaxies varies with galaxy environment at a fixed galaxy stellar mass Log SFR Log galaxy stellar mass

Poggianti et al SF-density = Morphology-density in high-z clusters Density Mean SFR SFing % For a given Hubble type, no trend of SF with local density

VIRIALIZED STRUCTURES AT HIGHER REDSHIFT WERE DENSER BOTH IN GALAXY NUMBER DENSITY AND (DM) MASS !!!……AND THE DENSITY DISTRIBUTION DOES NOT DEPEND ON CLUSTER/GROUPS MASS !!! Poggianti et al Projected local density distribution Physical (3D)Projected Z=0.6 z=0 Physical (3D) density distribution in structures of different masses

WHAT TIMESCALE? POST-STARBURST SPECTRA IN DISTANT CLUSTERS post-starburst galaxies 25% of the distant cluster galaxy population Dressler & Gunn 1983, Couch & Sharples 1987, Dressler et al. 1999, Poggianti et al. 1999, Tran et al. 2001, 2004 Larger % in clusters than in field at similar z’s (Dressler et al. 1999, Poggianti et al. 1999, Tran et al. 2003,2004, now Ediscs, Ma et al… – but Balogh et al. 1999) SF truncation in clusters strong Balmer absorption and no line detected in emission SF ended abruptly sometime during the last Gyr

Poggianti et al. 2009a At z= , post-starburst galaxies more frequent in more massive clusters and in some of the groups… …those groups with a low OII fraction for their sigma Massive S0 and Sa in transition More massive clusters have a higher proportion of k+a galaxies… Dusty starburst candidates are frequent in all environments, and are especially frequent in groups In EDisCS we find that the incidence of k+a galaxies at our redshifts depends strongly on environment

GROUP “BIMODALITY” ? THE KEY? Evidence: some groups look like “mini-clusters”, some look like field (at the same mass) for their star forming fraction, morphologies, post- starburst incidence etc Poggianti et al. 2006, 2008, 2009a, Wilman et al. 2005, 2009, Kautsch et al. 2008, Jeltema et al – also Zabludoff & Mulchaey 1998…. Not simply “true” vs “false” groups? (eg. X-ray groups Jeltema et al. 2007) – hard to explain as wrong mass estimate Difference between two types of groups ought to help to understand what is going on at the group level

Stay tuned for galaxy stellar mass functions as a function of environment, redshift and morphological type (Vulcani et al. in prep.) !!

For the Hall of Fame: An open question (two…): What is/are the physical process/esses responsible for the two passive families? Eg. From cold to hot gas accretion in massive haloes at high-z (primordial), and some “classic” environmental effects at lower-z (quenched)? Can it be the same process? How can we actually DISCRIMINATE OBSERVATIONALLY? Why are some groups efficient at turning star-forming, late-type galaxies into passive, early-type galaxies and some are not? What are the physical processes involved? The population of cluster and groups passive galaxies today is composed of two families: “primordial”, massive galaxies that finished forming stars at z≥2 (massive ellipticals – 20% of today’s 80% passive galaxies in clusters), and “quenched/declining” galaxies that stopped forming stars at later epochs due to a combination of intrinsic properties and environmental effects (mostly S0s, mostly non massive, and not all of the S0s, 50-60% of today’s 80%)