すばるが見た遠方銀河団 distant clusters of galaxies: take a closer look masayuki tanaka...
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すばるが見た遠方銀河団distant clusters of galaxies: take a closer look
Masayuki Tanaka (University of Tokyo)
Tadayuki Kodama (NAOJ) + PISCES team
picture credits: Sloan Digital Sky Survey, Robert Lupton (Princeton)
Outline
1 – Introduction
1-1 Environmental Dependence of Galaxy Properties
2 – Large-Scale Structures at z<1.2
2-1 Observational Data
2-2 Large-Scale Structures
3 – The Build-up of the Color-Magnitude Relation
3-1 Definitions of Environments
3-2 Color-Magnitude Diagrams
4 – Summary
1-1 Environmental Dependenceof Galaxy Properties
cluster galaxies field galaxies
environment galaxy density
Galaxies in low-density environments
NGC5668
Galaxies in high-density environments
Coma cluster
The environmental dependence of galay morphology was first quantified by Dressler 1980 (ApJ, 236, 351)
Morphology-Density Relation
galaxy density high low
popu
latio
n fr
actio
n
S0ESp + Irr
PISCES Project
- is a systematic survey of galaxy clusters at 0.4<z<1.2
Kodama et al. 2005, PASJ, 57, 309
Outline
1 – Introduction
1-1 Environmental Dependence of Galaxy Properties
2 – Large-Scale Structures at z<1.2
2-1 Observational Data
2-2 Large-Scale Structures
3 – The Build-up of the Color-Magnitude Relation
3-1 Definitions of Environments
3-2 Color-Magnitude Diagrams
4 – Summary
2-1 Observational Data
Mauna Kea Observatories
redshift
z=0
z=1.24(8.6Gyr)
z=0.55(5.4Gyr)
z=0.83(7.0Gyr)
Source Photometry Spectroscopy
Sloan Digital Sky Survey u g r i z ~260,000 objects(DR2)
Suprime-Cam (Subaru) B V R i z FOCAS (Subaru) ~200 objects
Suprime-Cam (Subaru) V R i z FOCAS (Subaru) ~300 objects
Suprime-Cam (Subaru) V R i z WFCAM (UKIRT) K
CL0016+16
RXJ0152
RDCS1252
Photometric Redshifts
CL0016 @ z=0.55 RXJ0152 @ z=0.83
idea:galaxies at different redshifts have different observed colors.
How accurate is it?
2-2 Large-Scale Structures
Mauna Kea Observatories
CL0016 at z=0.55
ACS/HST
Color composition by Ichi Tanaka
Large-Scale Structures
CL0016 at z=0.55
Large-Scale Structures
CL0016 at z=0.55
real structures!Hoshi et al. in prep.
RXJ0153 at z=0.83Color composition by Ichi Tanaka
Large-Scale Structures
RXJ0152 at z=0.83
Large-Scale Structures
RXJ0152 at z=0.83
Large-Scale Structures
RXJ0152 at z=0.83
z=0.844
z=0.842
z=0.745
z=0.782
z=0.835
z=0.837
z=0.839
z=0.844
RDCS1252 at z=1.24
Large-Scale Structures
RDCS1252 at z=1.24
Outline
1 – Introduction
1-1 Environmental Dependence of Galaxy Properties
2 – Large-Scale Structures at z<1.2
2-1 Observational Data
2-2 Large-Scale Structures
3 – The Build-up of the Color-Magnitude Relation
3-1 Definitions of Environments
3-2 Color-Magnitude Diagrams
4 – Summary
3-1 Definition of Environments
RDCS1252 (z=1.24) is not used from now on.
Cluster / Group / Field Environments
redshift
z=0 z=0.55 z=0.83
2-4 Colour-Magnitude Diagrams
Mass
Time
Galaxy Colours
Environment
Colour-Magnitude Diagrams
red
blue
z=0 z=0.55 z=0.83
redshift
massive less massive
Colour-Magnitude Diagrams
red
blue
z=0 z=0.55 z=0.83
redshift
massive less massive
2) 'Down-sizing' is delayed in low-density environments.
1) Galaxies follow the 'down-sizing' evolution.
Outline
1 – Introduction
1-1 Environmental Dependence of Galaxy Properties
2 – Large-Scale Structures at z<1.2
2-1 Observational Data
2-2 Large-Scale Structures
3 – The Build-up of the Color-Magnitude Relation
3-1 Definitions of Environments
3-2 Color-Magnitude Diagrams
4 – Summary
Schematic View of Galaxy Evolution
Env
iron
men
t
MassTime
Env
iron
men
t
MassTime
Schematic View of Galaxy Evolution
Env
iron
men
t
MassTime
Schematic View of Galaxy Evolution
Env
iron
men
t
MassTime
Schematic View of Galaxy Evolution
Env
iron
men
t
MassTime
Schematic View of Galaxy Evolution
Env
iron
men
t
MassTime
Schematic View of Galaxy Evolution