すばるが見た遠方銀河団 distant clusters of galaxies: take a closer look masayuki tanaka...

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