life before the fall: group galaxy evolution prior to cluster assembly anthony gonzalez (florida)...
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Life Before the Fall:Group Galaxy Evolution
Prior to Cluster Assembly
Life Before the Fall:Group Galaxy Evolution
Prior to Cluster Assembly
Anthony Gonzalez (Florida)Kim-Vy Tran (CfA)
Michelle Conbere (Florida)Dennis Zaritsky (Arizona)John Moustakas (Arizona)
Anthony Gonzalez (Florida)Kim-Vy Tran (CfA)
Michelle Conbere (Florida)Dennis Zaritsky (Arizona)John Moustakas (Arizona)
Ringberg Workshop - October 25, 2005
Hierarchical Assembly: SG1120Hierarchical Assembly: SG1120
Detection: Las Campanas Distant Cluster Survey (Gonzalez et al. 2001) 4 candidates at z~0.4 within
a 7’ diameter region
Confirmation: Chandra + spectroscopy 6 extended sources within a 13’ diameter region (~4 Mpc)
Groups at z=0.37 (2,3,4,5) Cluster at z=0.48 (1) No redshift yet (6)
“Supergroup” SG1120-1202
Detection: Las Campanas Distant Cluster Survey (Gonzalez et al. 2001) 4 candidates at z~0.4 within
a 7’ diameter region
Confirmation: Chandra + spectroscopy 6 extended sources within a 13’ diameter region (~4 Mpc)
Groups at z=0.37 (2,3,4,5) Cluster at z=0.48 (1) No redshift yet (6)
“Supergroup” SG1120-1202
Ringberg Workshop - October 25, 2005
Hierarchical Assembly: SG1120Hierarchical Assembly: SG1120
VLT BVR
Imaging
VLT BVR
Imaging
4
3
Ringberg Workshop - October 25, 2005
Spectroscopic ConfirmationSpectroscopic Confirmation
VLT Spectroscopy
101 confirmedmembers
VLT Spectroscopy
101 confirmedmembers
Ringberg Workshop - October 25, 2005
Redshift DistributionRedshift Distribution
Merging Galaxy GroupsMerging Galaxy Groups
``Virialized’’ Halos``Virialized’’ HalosMerging Galaxy GroupsMerging Galaxy Groups
``Virialized’’ Halos``Virialized’’ Halos
DispersionsDispersions
AllAll 62062050 50 km/skm/s
Group 3Group 3 37037080 80 km/skm/s
Group 4Group 4 45045080 80 km/skm/s
Group 5 Group 5 56056090 90 km/skm/s
DispersionsDispersions
AllAll 62062050 50 km/skm/s
Group 3Group 3 37037080 80 km/skm/s
Group 4Group 4 45045080 80 km/skm/s
Group 5 Group 5 56056090 90 km/skm/s
Gonzalez et al. 2005
Ringberg Workshop - October 25, 2005
Mass and DynamicsMass and Dynamics
Mass Tx (sum of individual groups 2-5): 5x1014 M
- lower limit Dynamical Analysis
Gravitationally bound Should merge by z~0 Additional velocities for groups 2,6 will refine this constraint
Should evolve in to a Coma-ish cluster by z=0
Mass Tx (sum of individual groups 2-5): 5x1014 M
- lower limit Dynamical Analysis
Gravitationally bound Should merge by z~0 Additional velocities for groups 2,6 will refine this constraint
Should evolve in to a Coma-ish cluster by z=0
Ringberg Workshop - October 25, 2005
Galaxy Evolution in GroupsGalaxy Evolution in GroupsComa Cluster (z~0.02)Coma Cluster (z~0.02)
SG1120 (z=0.37)Coma Progenitor
Ringberg Workshop - October 25, 2005
Galaxy Evolution in GroupsGalaxy Evolution in Groups
Key Questions Morphological Evolution Quenched/Enhanced Star Formation
E+A’s Fraction of star-forming galaxies; total star formation rate
Galaxy Mass Assembly HOD Interaction Rate Wet/Dry Mergers
Relation of above quantities to local density and galaxy mass
Key Questions Morphological Evolution Quenched/Enhanced Star Formation
E+A’s Fraction of star-forming galaxies; total star formation rate
Galaxy Mass Assembly HOD Interaction Rate Wet/Dry Mergers
Relation of above quantities to local density and galaxy mass
Ringberg Workshop - October 25, 2005
Galaxy Evolution in GroupsGalaxy Evolution in Groups
Method Morphological Evolution (ACS - 10 orbit F814 mosaic)
Quenched/Enhanced Star Formation E+A’s (VIMOS spectra, MIPS 24 m)
Fraction of star-forming galaxies; total star formation rate
Galaxy Mass Assembly (BVRJKS, ACS+WFPC2) HOD Interaction Rate Wet/Dry Mergers
Relation of above quantities to local density and galaxy mass(Chandra, ACS, BVRJKs imaging, MIPS, spectroscopy)
Method Morphological Evolution (ACS - 10 orbit F814 mosaic)
Quenched/Enhanced Star Formation E+A’s (VIMOS spectra, MIPS 24 m)
Fraction of star-forming galaxies; total star formation rate
Galaxy Mass Assembly (BVRJKS, ACS+WFPC2) HOD Interaction Rate Wet/Dry Mergers
Relation of above quantities to local density and galaxy mass(Chandra, ACS, BVRJKs imaging, MIPS, spectroscopy)
Ringberg Workshop - October 25, 2005
Color-Magnitude DiagramColor-Magnitude Diagram
Established Red Envelope
Retains Population of Starforming Galaxies
Intermediate between Field/Clusters
Established Red Envelope
Retains Population of Starforming Galaxies
Intermediate between Field/Clusters
FForeground/Background
Ringberg Workshop - October 25, 2005
Passive FractionPassive Fraction
Pre-processing
618% passive - Roughly twice as many
as field (same z)
Ringberg Workshop - October 25, 2005
Member Galaxies and Interactions
Member Galaxies and Interactions
Ringberg Workshop - October 25, 2005
SummarySummary
SG1120 is a confirmed “supergroup” at z=0.37 Gravitationally bound system 4-5 member groups within target region Direct view of progenitors of massive cluster
Well-defined red envelope Strong correlation between surface density and passive fraction
Ongoing mergers of massive galaxies, high merger fraction
SG1120 is a confirmed “supergroup” at z=0.37 Gravitationally bound system 4-5 member groups within target region Direct view of progenitors of massive cluster
Well-defined red envelope Strong correlation between surface density and passive fraction
Ongoing mergers of massive galaxies, high merger fraction
Ringberg Workshop - October 25, 2005
Work in ProgressWork in Progress
ACS Mosaic (10 orbit F814W) Morphological fractions and morphology-density
relation Interaction rate
MIPS - dusty star formation Additional spectroscopy
E+A fraction Fundamental plane Finish mapping superstructure
ACS+Chandra+spectra Cross-correlation between local density and X-ray
surface brightness SED and morphology vs X-ray surface brightness
Comparison with properties of both local clusters (Coma) and CL 1358 (z=0.33)
ACS Mosaic (10 orbit F814W) Morphological fractions and morphology-density
relation Interaction rate
MIPS - dusty star formation Additional spectroscopy
E+A fraction Fundamental plane Finish mapping superstructure
ACS+Chandra+spectra Cross-correlation between local density and X-ray
surface brightness SED and morphology vs X-ray surface brightness
Comparison with properties of both local clusters (Coma) and CL 1358 (z=0.33)