Wide-field Imaging + Spectroscopic Survey of Distant Clusters
description
Transcript of Wide-field Imaging + Spectroscopic Survey of Distant Clusters
Wide-field Imaging + Spectroscopic Survey
of Distant Clusters
Masayuki Tanaka (ESO)
Outline of this talk
1 – PISCES project
2 – Large-scale structures around distant clusters
3 – Build-up of the red sequence at z<1.3
4 – Spectral Diagnostics
5 – From the Cradle to the Grave
6 – Summary
1 – PISCES project
outline
1 – pisces project
2 – large-scale structures around distant
clusters
3 – the build-up of the red sequence
4 – spectral diagnostics
5 – from the cradle to the grave
6 – summary
Pi·sces [pahy-seez, pis-eez]
-n. 1. A constellation in the equatorial region of the Northern Hemisphere
near Aries and Pegasus. Also called Fishes.
2. a. The 12th sign of the zodiac in astrology. Also called Fishes.
b. pl. Pisces One who is born under this sign. 3. A deep, wide-field survey of galaxy clusters at 0.4<z<1.3.
PISCES project (in A&A abstract format)
For details, see Kodama+ 2005 PASJ, 57, 309
Aims:
Methods:
Results:
Conclusions:
Our goal is to quantify galaxy properties as functions of
environment, mass, and time and understand how and when the
environmental dependence of galaxy properties is established.
We carry out a systematic, deep (~M*+4), wide-field (30’x30’),
optical-nearIR imaging + spectroscopic survey of distant clusters.
Some of our recent results are presented in this talk.
Our survey is not finished yet, so…..we will see.
ACS/
HST
CL0016+16 at z=0.55
BVRiz photometry + 150 spec. objects
RXJ0152-13 at z=0.83
VRizK photometry + 200 spec. objects
RDCSJ0910 at z=1.1
VRizK photometry + some spec. objects
RDCSJ1252 at z=1.24
VRizK photometry + some spec. objects
2 – Large-scale structures
around distant clusters
Large-scale structure in the local Universe
outline
1 – pisces project
2 – large-scale structures around distant
clusters
3 – the build-up of the red sequence
4 – spectral diagnostics
5 – from the cradle to the grave
6 – summary
~70,700 objects~3,600 objects
0.48<zphot<0.60
Large-Scale Structures at z=0.55
CL0016 at z=0.55 (Tanaka+ MNRAS, 2007, 379, 1546)
~3,600 objects
0.48<zphot<0.60
Large-Scale Structures at z=0.55cluster redshift
CL0016 at z=0.55 (Tanaka+ MNRAS, 2007, 379, 1546)
Large-Scale Structures at z=0.83
RXJ0153 at z=0.83Tanaka+ 2006 MNRAS, 365, 13920.76<zphot<0.88
red galaxies
blue galaxies
RXJ0153 at z=0.83
Large-Scale Structures at z=0.83
z=0.844
z=0.842
z=0.745z=0.782
z=0.835
z=0.837
z=0.839
z=0.844
spec. objects at
0.82<z<0.85
0.76<zphot<0.88
Large-Scale Structures at z=1.1
RDCSJ0910 at z=1.1
RDCSJ1252 at z=1.24
Tanaka+ 2007a MNRAS, 377, 1206
Large-Scale Structures at z=1.2
1.17<zphot<1.31
Close-up views of the clumps
3 – Build-up of the red sequence
galaxies come in two flavours...red
blue
bright faintoutline
1 – pisces project
2 – large-scale structures around distant
clusters
3 – the build-up of the red sequence
4 – spectral diagnostics
5 – from the cradle to the grave
6 – summary
Colour-Magnitude Diagrams at z<0.83
blue
red
faintbright
Tanaka+ 2005 MNRAS, 362, 268
Colour-Magnitude Diagrams at z=1.1 (preliminary!)
RDCSJ0910 at z=1.1
Colour-Magnitude Diagrams at z=1.2
Main Cluster
Lidman et al. 2004 A&A
Composite Group
Tanaka et al. 2007a MNRAS
18 20 22 24 26
Ks
18 20 22 24
Ks
RDCSJ1252 at z=1.24
Colour-Magnitude Diagrams at z=1.2
Main Cluster
Lidman et al. 2004 A&A
Composite Clump
Tanaka et al. 2007a MNRAS
1 – The bright-end of the red sequence appears first
and the faint end appears later.
2 – The build-up of the red sequence is ‘delayed’
in low-density environments.
4 – Spectral Diagnostics
outline
1 – pisces project
2 – large-scale structures around distant
clusters
3 – the build-up of the red sequence
4 – spectral diagnostics
5 – from the cradle to the grave
6 – summary
z=1.24
z=1.1
z=0.83
z=0.81
z=0.55
z=0
: RDCSJ1252
: RDCSJ0910
: RXJ0152
: RXJ1716
: CL0016
: Sloan Survey
composite spectra of red galaxies at z~0.8
composite spectra of red galaxies at z~0.5
composite spectra of red galaxies at z=0
Spectral Diagnostics
Redshift Field Group Cluster z~0.8
z~0.5
z~0
No clear CMR CMR at bright end Tight CMR
CMR at bright end Tight CMR Tight CMR
Red galaxies are consistent with passive evolution
no [OII], no strong Hd
EW[OII]=14A EW[OII]=4A No [OII]
EW[OII]=4A No [OII] No [OII]
No strong Hd Strong Hd No strong Hd
Strong Hd No strong Hd No strong Hd
The strong Hd is suggestive of a sharp decline in star formation rates.
Fast Facts of Environmental Mechanisms
galaxy-galaxy interactions <<1Gyr field/group
harassment ? cluster
ram-pressure stripping <<1Gyr cluster
strangulation ~1Gyr group/cluster
mechanisms star formation effective env.
Fast Facts of Environmental Mechanisms
galaxy-galaxy interactions <<1Gyr field/group
harassment ? cluster
ram-pressure stripping <<1Gyr cluster
strangulation ~1Gyr group/cluster
mechanisms star formation effective env.
For more detailed discussions, see Tanaka+ 2007 MNRAS, 379, 1546
5 – From the Cradle
to the Grave
outline
1 – pisces project
2 – large-scale structures around distant
clusters
3 – the build-up of the red sequence
4 – spectral diagnostics
5 – from the cradle to the grave
6 – summary
Clusters at z=0 are filled with
red and dead galaxies.
Clusters at High/Low Redshifts
Proto-clusters at z=5.7 can be traced
by young, forming galaxies
(Ouchi+ '05).
Galaxy clusters change their nature from the cradle to the grave...
Key question : “How and when do they change?”“How and when do they change?”
Key epoch: redshift around 2
RDCSJ1252 cluster at z=1.24
(Tanaka+ '07): Red gals have already
become the dominant population.
PKS1138 cluster at z=2.16
(Kurk+ '04): Red and blue gals co-
exit?
Probing z~2 clusters would give us a hint for the origin
of the environmental dependence of galaxy properties.
6 – Summary
outline
1 – pisces project
2 – large-scale structures around distant
clusters
3 – the build-up of the red sequence
4 – spectral diagnostics
5 – from the cradle to the grave
6 – summary
Oktoberfest in Munich
Summary Galaxies follow the 'environment-dependent down-sizing' evolution. Galaxy-galaxy interactions may be the driving process of this evolution. Probing clusters at z~2 with next generation surveys would be interesting.
En
viro
nm
en
t
Mas
s