High Resolution Measurements of CMB Anisotropies with ACBAR U.C. Berkeley: W.L. Holzapfel (co-PI) M.D. Daub M. Lueker Case-Western: J. Ruhl (co-PI) J. Goldstein JPL/Caltech: J.J. Bock C.L. Kuo A.E. Lange C. Reichardt CMU: J.B. Peterson Sussex: A.K. Romer L. Valkonen Cardiff: P.A. Ade Around the World M.C. Runyan ACBAR is funded by the NSF Office of Polar Programs ACBAR Collaborators

ACBAR was built to: (Gomez et al. 2003) Measure the CMB temperature anisotropies Search for new SZ clusters Make targeted multi- SZ observations of clusters. (White, Hernquist, & Springel 2002) ACBAR’s coverage WMAP

CMB Power Spectrum CMB physics is well- understood and calculable (linear regime: d cdm ~10 -3 ) Experiments measure exactly what theory predicts! What is the universe made of? What drives its dynamics? How did structure form? (C. Lineweaver, 2003) Plasma falling into a dark matter overdensity

The Damping Tail Photon diffuse out of over-dense regions & carry baryons with them. The acoustic oscillator has a Q~5. The damping scale measures the angular scale of Silk length at recombination: Silk length ~ 3.5 Mpc (  m /  b ) 1/2 (  m h 2 ) -3/4 An independent measure of cosmological parameters Break degeneracies Test for new physics (W. Hu, 2002)

ACBAR: Instrument and Observations Winterover

Special Thanks to our Crazy Winter-overs Helium fill: Winter 2002 Matt Newcomb, 2001 & 2002 Justus Brevik 2004 Jessica Dempsey 2005

Cooled to 230mK He3/He3/He4 Fridge 24-hour hold time Arcminute Cosmology Bolometer Array Receiver 4K 350mK 230mK FET 120K JPL MDL Bolometers 16-element array Corrugated feed horns

Picture and bolometer provided by JPL Microdevices Lab ACBAR Bolometers Fast (~3 ms) Broadband Very sensitive Map 1 deg 2 to 10  K per beam at 150 GHz in ~3h. #Band (GHz) T RJ (K) NET CMB (  K  s) 8x (added 2005) x

The Viper Telescope Schematic diagram of the optics (2m off-axis Gregorian) Triangular wave 0.3 Hz, 3 º peak to peak Large Chop (~3˚) + small beams = wide - range Ground shield blocks emission from EL < 25˚

Optimizing the Analysis CMB5 Field Winter 2002 CMB5 field, M-(L+T)/2 CMB5, un-differenced Cosmic Variance: 3x area Noise: S/N improves by 8/3 No-LMT Scan with nearly constant elevation

Calibration CMB Dipole WMAP Boomerang ACBAR Galactic sources mapped multiple times per day. Used to construct pointing model and calibration Raster map of RCW38 B03 observed RCW38 at 150 GHz too! 6% calibration in temperature

Foregrounds Avoids foregrounds: Dust Radio sources Plenty of low- dust sky available year- round

Radio sources: cmb5 Sources in the PMN radio source catalogue are removed in the PS analysis. Monitor beam size and pointing with mm-bright point sources in each field.

Black: ACBAR new analysis Red: ACBAR 2002 release Green: CBI No-LMT Power Spectrum – preview New analysis method (no-LMT) Improved calibration 2x more sky

More to come from ACBAR! 2004: 5 months of observation Instrument unchanged from : Full winter of observation Reconfigured the focal plane to double the number of detectors at 150 GHz 6.5x More Sky & 3.7x More Time! ACBAR B03 Improved Calibration Portion of B03 Deep Field

Full ACBAR Dataset Measure the higher acoustic peaks and damping tail of the power spectrum with high signal-to- noise Improve calibration by factor of 2-3 –Even better with WMAP 4 th year! Improve estimates of  m,  b, n s, dn s /dlnk …

Hu, 2001, ApJL Lensing probes the large scale matter distribution using smaller objects with known (average) shape The growth of large scale structure depends critically on dark energy Challenge: CMB is a gaussian random field w/o fixed shape UnlensedLensed ACBAR’s deep fields should have 2-3 sigma detection. Really Massive Source Lensing

CBI’s High- Excess Point Sources –Radio sources –dusty galaxies Non-standard Inflation SZE 355  103  K 2 at 30 GHz Cooray & Melchiorri, 2002 astro-ph/ Predictions: Non-standard inflation: power equal at 150 GHz SZ excess: power reduced by ~4 at 150 GHz

High- Excess? SZ results in a ratio 4 for the observed powers. Looking good: SZE from clusters, SZE from pop. III stars.. NOT looking good: primordial magnetic fields, primordial voids… SZ Primordial… CBI BIMA ACBAR Goldstein et al. astro-ph/ Dawson et al. LMT Analysis: consistent with either Reanalysis (no-lmt) of 2002 Data

Summary ACBAR has measured CMB temperature anisotropies with high S/N to > 2000 –Paper coming out soon Analysis is underway to: –Calibrate with CMB anisotropies to WMAP and B03 –Improved power spectrum measurement by including nearly 4x more data and 7x more sky from last winter. –Detect Gravitational Lensing –SZ clusters Pointed Observations Blind search for unknown clusters

The End