Chao-Lin Kuo Stanford Physics/SLAC ACBAR Chao-Lin Kuo Stanford Physics/SLAC

CMB power spectrum, as of 03/04/08 mK2

ACBAR – power spectrum final results On the preprint arxiv: 01/10/08 (astro-ph 08011491) For this data release, esp.: Christian Reichardt (Caltech→Berkeley) Bill Holzapfel Chao-Lin Kuo (Caltech→Stanford) Andrew Lange Carlo Contaldi Dick Bond Planning/ operation Cosmological parameters

Arcminute Cosmology Bolometer Array Receiver (2001-2005) corrugated feed horns South pole 2 meter Telescope @ South Pole Cooled to 240mK He3/He3/He4 Fridge Bolometers 2 meter mirror + 150 GHz = High resolution (4.8’) Map = 11x2.5 deg The largest scale structures (>1 deg) have been filtered All structures are real, larger than the beam size sum diff

The CMB damping tail The damping scale measures the angular scale of Silk length at recombination: Silk length ~ 3.5 Mpc (m/ b)1/2 (mh2) -3/4 Dunkley et al, today

Sky Coverage Year observed: 2001 2002 2005 Kuo, 2004; 16.8 khours ; 63 deg2 Kuo, 2007; 23.0 khours ; 137 deg2 Reichardt 2008; 85.4 khours ; 710 deg2 Year observed:

ACBAR PS Releases R08 ACBAR 2004; differenced; 63 deg2; 10.% calibration (Temperature) ACBAR 2007; undifferenced; 137 deg2; 6.0% calibration Reichardt 2008; undifferenced ; 710 deg2; 2.3% calibration

Foregrounds Calibration FDS (1) Galactic dust 0.5% CMB Dipole FDS (done by WMAP) 0.5% ACBAR favors a lower amplitude: 0.1±0.5 Good news for future polarization exp. (2) Radio point sources Estimated residual: 2.2 (/2600)2 K2 (done by C Reichardt) ACBAR 2.3% (3) High-z galaxies Estimated residual:: 9-16 (/2600)2 K2

Cosmological implications The most important result: WMAP-3 model spectrum is a very good fit (flatness, L, CDM, …) This seriously limits non standard ingredients. Important note: Beam uncertainty (published function) Calibration uncertainty (2.3% in T) CBI/BIMA: 355  103 K2 at 30 GHz* ACBAR 34  20 K2 at 150 GHz High-l CBI excess is not primordial*

1D likelihoods WMAP3 WMAP3+ ACBAR CMBall More details: No major surprises. (Very consistent with WMAP3 model!) Adding ACBAR’s small scale information shifts c &  by 1 . More details: astro-ph/08011491

Where the constraining power is coming from- The 3rd peak.. ACBAR WMAP BOOM 500 1000 1500 2000 Slosar

2-D parameter contours q ns

Lensing with ACBAR Lensed Unlensed Method 1: Power spectrum: * ACBAR’s band-power’s are consistent with a 6-parameter CDM model. * Lensed models are favored (~3.1) when ACBAR is added to WMAP3. Method 2: Higher order statistics – lens reconstruction * Generalize Hu’s quadratic estimator for a map with spatial filters and non-uniform coverage * ACBAR’s pixel-based maximum likelihood algorithm easy to generalize for lensing work. (CK, Dan Babich,..) * Maximum likelihood analysis by Hirata&Seljak serves as an important guide line

The Quest for “B” BICEP & future ACBAR QUAD/DASI/SPUD BICEP

CMB polarization and current measurements E-mode B-mode (gravity waves) (lensing) Re-ionization r = 0.05 E B → The lensing B-mode – a probe of the large scale structure Dark Energy – equation of state, evolution Absolute neutrino mass (down to ~0.05 eV) Geometry The re-ionization bump (early re-ionization ) The E-mode polarization – adiabatic vs isocurvature modes

Ongoing @ South Pole: the BICEP Experiment H. Chiang Small telescope Cold, stable refractive optics

Bolometric Polarimeters The state-of-the-art (QUAD, BICEP): The future: Co-locating dual-polarization polarimeter High optical efficiency, wide band Extremely stable Nice beam/band Low polarization artifacts Discrete elements: feeds, filters, detectors To integrate all these components on a Si wafer → mass production Higher packing density TES enables SQUID multiplexed read-out 30 cm 8 cm Antenna-coupled TES array (64 detector pairs) BICEP focal plane (98 detectors)

Enabling Technology: lithographic detectors Al Load resistor Ti Dual-Tc TES bolometer 7.5 mm (150 GHz) Dual-polarization antenna/summing network 25 % Bandwidth Compact LC Filter 0.8 mm

2008 2009-2010