SZ Surveys Are Coming: What should we do?

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SZ Surveys Are ComingWhat should we do?

• James G. Bartlett
• APC - Université Paris 7

Collabs J.-B. Melin (CEA), J. Delabrouille
(APC), S. Mei (JHU)
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Aims

• Coming breakthrough at z1 hundred-fold increase
  in galaxy cluster numbers
• Taste for the science with clusters
• Importance of SZ effect
• Some catalog construction issues
• More studies needed

J. Bartlett
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SZ Surveying Projects

• Interferometers 10-100 sq. deg.
• Arcminute MicroKelvin Imager (AMI) (in operation)
  first image astro-ph/0509215
• 10 antennas (3.7m), 15 GHz, Ryle Telescope
• Array for Microwave Background Anisotropy (AMIBA)
• 19 antennas (0.3m), 90 GHz, Hawaii
• SZ Array (in operation)
• 8 antennas (3.5m), 30 GHz 90GHz follow-up,
  OVRO/BIMA
• Bolometer arrays 100-4000 sq. deg.
• ACBAR 4 band-4element array at South Pole
  (in operation)
• BOLOCAM 150 element array
  (in operation)
• APEX ALMA prototype, 300 element array
  (2006)
• ACT Atacama plateau, 1000 element array
  (2006)
• SPT 10m dish, 1000 element array
  (2007/2008)
• Planck launch 2007/2008, all-sky
• 10,000 clusters

J. Bartlett
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Galaxy Clusters
Galaxies
Early types
10 - 1000
poor groups - rich clusters
POSS
Gas
Heated by infall
Chandra
Dark Matter
J. Bartlett
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Cosmology with Clusters

• Environment for galaxy formation studies
• Interplay between stars, galaxies, gas dark
  matter
• Stellar mass build-up Hubble sequence
  transformations
• Feedback/cooling effects (over a large range of
  masses)
• Efficient tracers of large-scale structure
• good sampling, simple bias
• Baryon acoustic oscillations
• Properties and evolution are sensitive to
  cosmology
• density perturbations
• Cosmological parameters e.g., dark energy
• Gaussianity of the perturbations
• Hubble diagram (SZ Xrays)

J. Bartlett
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Efficient Tracers of LSS

• Good sampling
• Simple bias (Mo White 1996)
• cluster halo

Clusters Mgt1014
SDSS LRGs
Clusters Mgt2x1014
Eisenstein et al. 2005, ApJ 633, 560
Sheth Tormen 1999
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Abundance Evolution
Cluster evolution constrains cosmological
parameters
?M
?M
?M
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Cluster Surveys
Need large, homogeneous (in mass) catalogs to zgt1
RDCS 0910 z1.11 Stanford et al. 2002
RXJ 1053 z1.14 Hashimoto et al. 2004
RDCS 1252 z1.24 Rosati et al. 2004
RDCS 0849 z1.26 Rosati et al. 1999
Lynx z1.27 Stanford et al. 1997
XMMU 2235 z1.39 Mullis et al. 2005
ISCS J1438 09 (IRAC) z1.41 Stanford et al. 2006
ISCS z1.37 Eisenhardt et al. 2005
ISCS z1.24
ISCS z1.11
Current list of spectroscopically confirmed zgt1
clusters from optical/NIR imaging X-ray
surveying
X-ray
Today 10 at zgt1
J. Bartlett
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Cluster SurveysMethods

• Optical/IR imaging Early type galaxy colors
  (e.g., darkCAM, DES, ISCS, LSST, Pan-starrs,
  RCS12 ,)
• Good contrast
• Relation to mass
• X-ray imaging Lx from hot gas (e.g., review by
  Rosati et al. 2002, XCS)
• Good contrast
• T tightly correlated to mass
• All-sky surveys - shallow
• Deeper serendipitous - limited area,
  inhomogeneous
• Weak lensing shear/aperture mass (e.g., DUNE,
  JDEM)
• Direct relation to mass
• Projection effects

J. Bartlett
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Surveying with the SZ Effect

• Doing cosmology with galaxy clusters
• The Sunyaev-Zeldovich (SZ) Effect
• Surveying
• The projects
• Catalog construction (J. Delabrouille - APC, S.
  Mei - JHU, J-B. Melin - SPP/CEA )
• Method evaluation
• Point source confusion
• Cluster morphology
• Conclusions

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Sunyaev-Zeldovich Effect(s)
T5 keV
(CL0016 Carlstrom et al.)
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Thermal SZ Effect
For y ltlt 1 and Tg/Te ltlt 1 (Ok for clusters)
x 6.51
x- 2.26
2.28 ?104 mJy/arcmin2
Compton y parameter
xo 3.83
10-4
d?
For Tcmb 2.726K
?-
?
?o
?- 128 GHz
?- 2.34 mm
?o 1.38 mm
?o 218 GHz
? 0.80 mm
? 370 GHz
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SZ Cluster Surveys
(Korolov et al, 1986, JGB Silk 1994, Barbosa et
al. 1996, Eke et al. 1996)
A SZ flux-limited survey
Important properties (Bartlett 2001)

• Efficient at high z
• ?i const, Ssz?Dang-2
• Spectral signature
• unique, no k-correction
• Ssz ? gas thermal energy
• robust, independent of spatial/
• thermal structure

J. Bartlett
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SZ Cluster Surveys
Y
Intrinsic scatter
Insensitive to mergers, thermal structure, etc
M
Motl et al. 2005, ApJ 623, L63
Planck 3?
Close to a mass selected catalog, uniform in
redshift
Detection mass
Ground 5?
Important for evolutionary studies - same kind
of object observed at different epochs
J. Bartlett
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SZ Surveying Projects

• Interferometers 10-100 sq. deg.
• Arcminute MicroKelvin Imager (AMI) (in operation)
  first image astro-ph/0509215
• 10 antennas (3.7m), 15 GHz, Ryle Telescope
• Array for Microwave Background Anisotropy (AMIBA)
• 19 antennas (0.3m), 90 GHz, Hawaii
• SZ Array (in operation)
• 8 antennas (3.5m), 30 GHz 90GHz follow-up,
  OVRO/BIMA
• Bolometer arrays 100-4000 sq. deg.
• ACBAR 4 band-4element array at South Pole
  (in operation)
• BOLOCAM 150 element array
  (in operation)
• APEX ALMA prototype, 300 element array
  (2006)
• ACT Atacama plateau, 1000 element array
  (2006)
• SPT 10m dish, 1000 element array
  (2007/2008)
• Planck launch 2007/2008, all-sky
• 10,000 clusters

J. Bartlett
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(Great) Expectations

• Cluster detection catalog construction method
• Spectro-spatial matched filter (Melin, JGB,
  Delabrouille 2005, 2006)
• Expected cluster numbers and redshift
  distributions
• Examine cluster catalog construction
  observational uncertainties
• Selection criteria
• Photometry

J. Bartlett
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Catalog Extraction
Melin, JGB, Delabrouille
Input clusters
Simulated observation

• 15 GHz simulation with
• primary CMB
• point sources lt 100 ?Jy
• fwhm2 arcmin
• noise 5 ?K/lobe

• Selection criteria
• Photometry

APC U. Paris 7
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Case Studies
Name Frequency (GHz) Beam FWHM (arcmin) Noise (?K/beam) S/N5 (deg-2) Total
AMI 15 1.5 8 16 150
SPT 150 1 10 11 40000
220 0.7 60
275 0.6 100
ACT 145 1.7 1.7 40 4000
225 1.1 4.8
265 0.93 7.8
Planck 143 7.1 6 0.35 10,000
217 5 13
353 5 40
3 deg
3 deg
Many simulations of each experimental setup
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Completeness
Primary CMB confusion
Not a pure flux limit
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Numbers at high z

Bartlett 2001
SPT 4000 deg2
100s of Planck clusters at zgt1 (unresolved)
1000s of SPT clusters at zgt1
Planck 30000 deg2
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Photometry - SPTRelation Yrec - Ytrue

• Small bias
• Scatter
• Much larger than
• instrumental noise
• Cluster-cluster confusion
• Significantly larger than
• predicted intrinsic scatter

APC U. Paris 7
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Photometry - AMIRelation Yrec - Ytrue
Problem caused by inability to determine cluster
core radius due to confusion with primary
CMB anisotropy
Requires follow-up in other wavebands
APC U. Paris 7
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Conclusions - I
Breakthrough at zgt1 10 --gt 1000s

• These new, large cluster catalogs will address
  key cosmological questions
• Galaxy formation
• Dark energy
  (e.g., Lima Hu 2005, Wang et al. 2004)
• SZ effect ideally suited for cluster surveying
• Efficient at high z
• Roughly uniform mass selection out to zgt1
  
• Expectations 2006-2010 10s gt 1000s _at_ zgt1
• Interferometers 100 (10 at zgt1)
• Bolometer cameras 1,000 - 10,000 (10 at zgt1)
• Planck 10,000 all sky (1 at zgt1)

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Conclusions - II

• Studying catalog construction
• (Vale White 2005, Pierpaoli et al. 2005,
  Melin et al. 2005, 2006)
• Selection function
• Point source confusion
• Calibration
• Simulations using rapid matched filter algorithm
• Catalog selection criteria Not Flux Limited
• Photometry
• Significant scatter
• Single frequency compromised - need follow-up
  (e.g., 90GHz)

J. Bartlett