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The Build-up of the Red Sequence at z<1.3 Masayuki Tanaka (ESO, not STScI) + Taddy Kodama (NAOJ)
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galaxies come in two flavours... red blue brightfaint
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Conclusion The bright end of the red sequence appears first and it extends to fainter mags., and the build-up of the red sequence is ‘delayed’ in low density environments. Galaxy-galaxy interactions may be a primary driver of this build-up. Environment Mass
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Outline of this talk 0 – Introduction 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 – Summary
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large-scale structure in the local universe 0 – Introduction outline 0 – introduction 1 – pisces prject 2 – large-scale structures in the distant universe 3 – the build-up of the colour-magnitude relation 4 – spectral diagnostics 5 – summary
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Galaxies in low-density environments... NGC5668
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Galaxies in high-density environments... Coma cluster
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The environmental dependence of galaxy morphology was first quantified by Dressler (1980, ApJ). Galaxy properties depend on environment galaxy densityhigh (cluster)low (field) population fraction S0 E Sp + Irr
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Clusters at higher redshifts CL0016 at z=0.55 taken with WFPC2 on HST
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? ? ? ? ? Clusters at higher redshifts CL0016 at z=0.55 taken with WFPC2 on HST Cluster outskirts and surrounding clumps/filaments remain unexplored. Also, faint galaxies at high redshifts have not been extensively examined yet. We carried out a wide and deep cluster survey.
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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 – 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.
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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.
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ACS/ HST CL0016+16 at z=0.55 BVRiz photometry + 150 spec. objects
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RXJ1716 at z=0.81 VRizK, H photometry + AKARI IR photometry
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RXJ0152-13 at z=0.83 VRizK photometry + 200 spec. objects
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RDCSJ0910 at z=1.1 VRizK photometry + some spec. objects
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RDCSJ1252 at z=1.24 VRizK photometry + some spec. objects
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RXJ0848 at z=1.27 VRizK photometry + some spec. objects Nakata et al. 2005 MNRAS, 357, 1357
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2 – Large-scale structures around distant clusters outline 1 – pisces project 2 – large-scale structures around distant clusters 3 – the build-up of the red sequence 4 – spectral diagnostics 5 – summary Large-scale structure in the local Universe
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~70,700 objects~3,600 objects 0.48<z phot <0.60 Large-Scale Structures at z=0.55 CL0016 at z=0.55 (Tanaka+ MNRAS, 2007, 379, 1546)
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~3,600 objects 0.48<z phot <0.60 Large-Scale Structures at z=0.55 cluster redshift CL0016 at z=0.55 (Tanaka+ MNRAS, 2007, 379, 1546)
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Large-Scale Structures at z=0.83 RXJ0153 at z=0.83 Tanaka+ 2006 MNRAS, 365, 1392 0.76<z phot <0.88 red galaxies blue galaxies
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Redshift distribution of spec. galaxies 0.76<z phot <0.88 cluster redshift RXJ0153 at z=0.83 Tanaka+ 2006 MNRAS, 365, 1392
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RXJ0153 at z=0.83 Large-Scale Structures 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 spec. objects at 0.82<z<0.85 0.76<z phot <0.88
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Large-Scale Structures at z=1.1 RDCSJ0910 at z=1.1
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RDCSJ1252 at z=1.24 Tanaka+ 2007a MNRAS, 377, 1206 Large-Scale Structures at z=1.2 1.17<z phot <1.31
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Close-up views of the clumps
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3 – Build-up of the red sequence outline 1 – pisces project 2 – large-scale structures around distant clusters 3 – the build-up of the red sequence 4 – spectral diagnostics 5 – summary galaxies come in two flavours... red blue brightfaint
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Cluster / Group / Field Environments For details of the definition, refer to Tanaka+2005 MNRAS
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Colour-Magnitude Diagrams at z<0.83 blue red faintbright Tanaka+ 2005 MNRAS, 362, 268
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Colour scatter around CMR z=0.83 z=0.55 z=0
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Colour scatter around CMR z=0.83 z=0.55 z=0
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Evolution of Fraction of red galaxies
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Color-Magnitude Diagrams at z=0.81 RXJ1716 cluster surrounding field Koyama et al. 2007 MNRAS submitted.
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Colour-Magnitude Diagrams at z=1.1 (preliminary!) RDCSJ0910 at z=1.1
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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
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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.
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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 – 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
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composite spectra of red galaxies at z~0.8
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composite spectra of red galaxies at z~0.5
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composite spectra of red galaxies at z=0
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Spectral Diagnostics...for details see Tanaka+07 MNRAS, 379, 1546
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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.
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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.
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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
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5 – Summary outline 1 – pisces project 2 – large-scale structures around distant clusters 3 – the build-up of the red sequence 4 – spectral diagnostics 5 – summary Ein Prosit, ein Prosit der Gemütlichkeit!
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Summary Galaxies follow the 'environment-dependent down-sizing' evolution. Galaxy-galaxy interactions may be the driving process of this evolution. Environment Mass
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