The E SO Dis tant C luster S urvey (EDisCS) Study evolution of cluster galaxies and clusters in 20 fields with clusters at z=0.4 – 1.0. - PowerPoint PPT Presentation
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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) The ESO Distant Cluster Survey (EDisCS) Study evolution of cluster galaxies and clusters in 20 fields with clusters at z=0.4 – 1.0 7 “ITALIANI”
Transcript
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 – 1.0
7 “ITALIANI”
• 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)
24 refereed papers published or submitted, + some ongoing studies.…. see Poggianti et al. June 2009 Messenger 136 54
RED GALAXIES
V-I
I magnitudeDe Lucia et al. 2004
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
Num
ber
ratio
of
red
lum
inou
s-to
-fai
nt g
alax
ies De Lucia et al. 2007
Deficit of faint, red galaxies in distant clusters compared to nearby clusters.
Rudnick et al. 2009
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 = 0.4-0.8 Sloan z = 0.04-0.1
Fra
ctio
n of
mem
bers
with
OII
w
ithin
R20
0
Velocity dispersion
10001000
500500
Poggianti et al. 2006
Desai et al. (2007)
(Dressler et al. 1997, Fasano et al. 2000, Postman et al. 2005, Smith et al. 2005 – 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. 2009 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. 2008
Morphology-density relation
Based on OII line
Poggianti et al. 2008
Anticorrelated Uncorrelated
Sta
r-fo
rmin
g fr
actio
n
Local density Mea
n(E
W)
of O
II g
alax
ies
Local density
STAR FORMATION-LOCAL DENSITY RELATION
Z=0 (red, SDSS clusters)
Z=0.4-0.8 (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. 2008
All galaxies (black)
SFing galaxies (blue)
Clusters + groups at z~0.4-0.8
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 – 0.6 Z = 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
SF
R
Log galaxy stellar mass
Poggianti et al. 2008
SF-density = Morphology-density in high-z clusters
Density
Mea
n S
FR
SF
ing
%
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. 2010
Projected local density distributionPhysical (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=0.4-0.8, 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. 2007 – 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%)
