Galaxy Clusters with The South Pole Telescope

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Galaxy Clusters withThe South Pole Telescope
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• Discover Clusters with SZ effect
• Sources are arcmin size
• SPT has 10 meter mirror
• SZ signal has distinct spectrum
• Observe in 90, 150, 220 GHz
• Signals are faint
• SPT has 1000 bolometers and large collecting
  area
• Signal magnitude independent of redshift
• Good news for us!

http//astro.uchicago.edu/sza/overview.html
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SPT ScienceDN/DZ with clusters

• Blind cluster search
• 4000 square degrees
• 90,150,220 GHz
• 10uK/arcmin pixel
• Thousands of clusters
• Many hundreds at high z
• Mass limited down to 2x1014 solar masses

G. Holder in Ruhl et al 2004
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SPT Science cont.High el CMB
Projected SPT
ACBAR 2008
Reichardt et al 2008
W. Hu from Ruhl et al 2004
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University of Chicago John Carlstrom (P.I) Steve
Padin (Proj. Manager, yr1 winter) Stephan
Meyer Clem Pryke Tom Crawford Jeff
McMahon Clarence Chang Kathryn Miknaitis Joaquin
Vieira Ryan Keisler Lindsey Bleem Abigail
Crites Year 2 winterovers Keith Vanderlinde
Dana Hrubes
University of Chicago John Carlstrom (P.I) Steve
Padin (Proj. Manager, yr1 winter) Stephan
Meyer Clem Pryke Tom Crawford Jeff
McMahon Clarence Chang Kathryn Miknaitis Joaquin
Vieira Ryan Keisler Lindsey Bleem Abigail
Crites Year 2 winterovers Keith Vanderlinde
Dana Hrubes
Berkeley William Holzapfel Adrian Lee Helmuth
Spieler Sherry Cho Bradford Benson Huan
Tran Martin Lueker Jared Mehl Tom Plagge Dan
Schwan Erik Shirokoff
Berkeley William Holzapfel Adrian Lee Helmuth
Spieler Sherry Cho Bradford Benson Huan
Tran Martin Lueker Jared Mehl Tom Plagge Dan
Schwan Erik Shirokoff
Case John Ruhl Tom Montroy Zak Staniszewski
(Me, yr1 Winterover) Wenyang Lu
UIUC Joe Mohr
McGill Matt Dobbs Gil Holder Trevor Lanting
UC Davis Lloyd Knox Jason Dick
Harvard Smithsonian Antony Stark
Colorado Nils Halverson
JPL Erik Leitch
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Large/Clean Telescope Design

• 10 meter primary
• 1arcminute resolution
• Off Axis design
• Low ground pickup
• Only 3 optical elements
• Ground shields (comoving inner)
• Under illuminated primary (7.5m)
• Cold baffle around secondary

Ground Shields
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Optics Cryostat
Cold absorbing baffle (10K)
foam window
Heat blocking filters
Secondary (10K)
Pulse Tube Cooler
Receiver
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Focal plane

• 960 superconducting bolometers
• Each of 6 wedges can be either 90,150 or 220 GHz
• Frequency multiplexed readout

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Focal Plane

• Key Points
• 2007 season
• Successfully deployed with 500 working bolos
• 2008 season
• Increased yield
• Increased bolo S/N
• Increased observing duty cycle
• 2009 season
• Plan on 90 GHz heavy array

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• SPT observing regions
• BCS optical data in green

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SPT observing regions

• 1st year
• 60 sq. degrees in BCS 5hr
• 40uK/arcmin pixel
• 5 sq. degrees inside previous region
• 15uK/arcmin
• 2nd year
• 100 sq degree 5hr
• 14 uK/arcmin at 150 GHz
• 100 sq degree 23hr
• Nearly completed at 15 uK/arcmin
• 4 x deep Targeted clusters images
• AS1063,Bullet,1ES0657,RDCS1252.9-2927
• 2 x Galactic HII regions
• RCW38,MAT5a
• 300 sq degree Wmap calibration
• Very shallow 14 hrs of observation

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Absolute calibration

• HII regions
• RCW 38, MAT5a
• Integrate RCW38 flux and compare to ACBAR or
  Boomerang
• WMAP
• Dedicated 14 hours to look at 300 sq.

RCW38 at 220 GHz (1 deg x 0.5
deg)
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SPT 150 GHz
Map Deleted for web posting
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WMAP V band (60 GHz)
Map Deleted for web posting
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100 square degree cluster finding field14
uK/arcmin pixel
Map Deleted for web posting
150 GHz LR map
150 GHz L-R difference map
Lleft going scans, Rright going scans
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Map Deleted for web posting
Bright point sources
Known cluster
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Matched filter of known cluster in 100 square
degree field
Known cluster. RXCJ0516.6-5430 (S0520) Z0.3
1.4x1045 ergs/s
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Year 1 maps
90 map
150 difference map
150 map
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Pointed cluster observations

• Bullet cluster
• 7x45 minute observations
• 14 uk/arcmin pixel
• R500 is 7
• Z0.3
• Use 220 to subtract CMB
• Other clusters targeted
• AS1063
• 1ES
• RDCS1252.0-2927

• Study scaling relations

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Pointing

• Bracketing Hii observations
• Make many single bolometer maps
• HII regions are separated in azimuth and
  elevation
• MAT5a,RCW38
• Confirm pointing in CMB maps
• Bright point sources have good s/n per obs.

MAT5a

• Pointing accuracy
• Absolute to 6
• Day to day jitter 10
• Improving daily

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SPT Focus and Beam Shapes
Fit each beam to 2-D Gaussian FWHMs measured
(predicted) 95 GHz 1.52 /- 0.08 (1.51) 150
GHz 1.08 /- 0.08 (1.01) 220 GHz 0.86 /-
0.05 (0.78)
Ellipticities measured (predicted) 95 GHz 1.08
/- 0.06 (1.03-1.08) 150 GHz 1.08 /- 0.06
(1.02-1.20) 220 GHz 1.12 /- 0.10 (1.02-1.27)
Beams Match Their Expected Shape Very Well
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Thank You