Imaging the Early Universe with ACBAR

William HolzapfelNSF 5/3/04

CMU:J.B. Peterson P. Gomez A.K. Romer

U.C. Berkeley:W.L. Holzapfel (co-PI)C.L. Kuo (now at CIT)M.D. Daub

M. Newcomb (2001/2002)Justus Brevik (2004)

Caltech:A.E. LangeM.C. Runyan(now at UC)C. Reichardt

Cardiff:P.A.R. Ade

Case-Western:J. Ruhl (co-PI)J. Goldstein

JPL:J.J. BockA.D. Turner

The Arcminute Cosmology Bolometer Array Receiver

ACBAR is funded by the NSF Office of Polar Programs

IRAS Dust Emission in the Southern Sky

Observes From South Pole

Viper Telescope: 2.0 meter off-axis

350 m tipper data: atmospheric noiseComparison

Arc

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Quartiles of PWV at three Sites

At each site, the year is divided into the best and worst 6-month periods.

Bars show quartiles of the PWV distribution at each site.

Because of its cold temperatures (annual average temperature –49 C), the South Pole is considerably drier than either Atacama or Mauna Kea.

SZ

Primary CMB

Atmospheric transmission

ACBAR as configured for 2002 Season

Viper refurbishment 1/2001

ACBAROn Viper

at the beginningof the 2002

winter season

Low z Clusters

1E0657-67 (z=0.299) at 3 frequencies

Decrement at 150, nothing at 220, increment at 275 GHz!

CMB5 FieldWinter 2002Highest S/NMap of the

CMBto date

S/N~100On degree

scale structure

WMAP, ACBAR and CBIBennett et al. astro-ph/0302207

Spergel et al., 2003

What does ACBAR add to parameter estimation from WMAP?

ACBAR and CBI were used as an “ext”ension to the WMAP power spectrum to help break parameter degeneracies.

ACBAR

WMAP

ACBAR

BOOMERanG WMAP

Three Identically processed mapsOf the same ~ 6 deg2 of sky.

Precise cross calibration from theCMB is now a possibility for BOOMERANG and ACBAR.

Cross calibration of ACBAR Boomerang and WMAP

Boom 98 CMB image

ACBAR 02 CMB image

B98 Sky coverage

ACBAR CMB2 Sky coverage

ACBAR Present and Future

•ACBAR is currently observing

•Instrument to be refurbished in summer 2005

•Final year of observations winter 2005

•Future of Viper? Potential for a next generation instrument?

Helium FillAugust 2002Matt Newcomb