Slide 1

ACBAR Chao-Lin Kuo Stanford Physics/SLAC Slide 2 K2K2 CMB power spectrum, as of 03/04/08 Slide 3 ACBAR power spectrum final results On the preprint arxiv: 01/10/08 (astro-ph 08011491) Christian Reichardt (CaltechBerkeley) Bill Holzapfel Chao-Lin Kuo (CaltechStanford) Andrew Lange Carlo Contaldi Dick Bond Planning/ operation Cosmological parameters For this data release, esp.: Slide 4 Arcminute Cosmology Bolometer Array Receiver (2001-2005) Cooled to 240mK He3/He3/He4 Fridge Bolometers corrugated feed horns 2 meter Telescope @ South Pole sum diff Map = 11x2.5 deg The largest scale structures (>1 deg) have been filtered All structures are real, larger than the beam size 2 meter mirror + 150 GHz = High resolution (4.8) South pole Slide 5 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 ( m h 2 ) -3/4 Dunkley et al, today Slide 6 Sky Coverage 2001 2002 2005 Year observed: Kuo, 2004; 16.8 khours ; 63 deg 2 Kuo, 2007; 23.0 khours ; 137 deg 2 Reichardt 2008; 85.4 khours ; 710 deg 2 Slide 7 ACBAR PS Releases ACBAR 2004; differenced; 63 deg 2 ; 10.% calibration (Temperature) ACBAR 2007; undifferenced; 137 deg 2 ; 6.0% calibration Reichardt 2008; undifferenced ; 710 deg 2 ; 2.3% calibration R08 Slide 8 Foregrounds ACBAR favors a lower amplitude: 0.10.5 Good news for future polarization exp. Calibration CMB Dipole (done by WMAP) (done by C Reichardt) ACBAR FDS 2.2 ( /2600) 2 K 2 (2) Radio point sources Estimated residual: (3) High-z galaxies Estimated residual:: 9-16 ( /2600) 2 K 2 2.3% 0.5% (1) Galactic dust Slide 9 Cosmological implications The most important result: WMAP-3 model spectrum is a very good fit (flatness, , CDM, ) This seriously limits non standard ingredients. Important note: Beam uncertainty (published function) Calibration uncertainty (2.3% in T) CBI/BIMA: 355 103 K 2 at 30 GHz* ACBAR 34 20 K 2 at 150 GHz High-l CBI excess is not primordial* Slide 10 1D likelihoods WMAP3 WMAP3+ ACBAR CMBall Adding ACBARs small scale information shifts c & by 1 . More details: astro-ph/08011491 No major surprises. (Very consistent with WMAP3 model!) Slide 11 500 10001500 2000 ACBAR WMAP BOOM A.Slosar Where the constraining power is coming from- The 3 rd peak.. Slide 12 2-D parameter contours nsns Slide 13 Lensed Unlensed Lensing with ACBAR Method 1: Power spectrum: * ACBARs band-powers 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 Hus quadratic estimator for a map with spatial filters and non-uniform coverage * ACBARs 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 Slide 14 The Quest for B BICEP & future ACBAR BICEP QUAD/DASI/SPUD Slide 15 CMB polarization and current measurements 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 E B E-mode B-mode (gravity waves) B-mode(lensing) Re-ionization r = 0.05 Slide 16 Ongoing @ South Pole: the BICEP Experiment Small telescope Cold, stable refractive optics H. Chiang Slide 17 BICEP focal plane (98 detectors) Antenna-coupled TES array (64 detector pairs) 30 cm 8 cm Bolometric Polarimeters Co-locating dual-polarization polarimeterCo-locating dual-polarization polarimeter High optical efficiency, wide bandHigh optical efficiency, wide band Extremely stableExtremely stable Nice beam/bandNice beam/band Low polarization artifactsLow polarization artifacts Discrete elements: feeds, filters, detectorsDiscrete elements: feeds, filters, detectors To integrate all these components on a SiTo integrate all these components on a Si wafer mass production wafer mass production Higher packing densityHigher packing density TES enables SQUID multiplexed read-outTES enables SQUID multiplexed read-out The state-of-the-art (QUAD, BICEP): The future: Slide 18 Enabling Technology: lithographic detectors 25 % Bandwidth Compact LC Filter Dual-Tc TES bolometer 7.5 mm (150 GHz) Al Ti Load resistor Dual-polarization antenna/summing network 0.8 m Slide 19 2008 2009-2010 Slide 20