2-year Total Intensity Observations 2000+2001

2. 1-year Polarization Observations 2003+2004 2-year Total Intensity Observations 2000+2001 Cosmic Background Imager Tony Readhead Zeldovich celebration Moscow December 2004

3. Caltech: (Cartwright*) Dickinson (Keeney) (Mason) (Padin (project scientist)) Pearson Readhead (Schaal) (Shepherd) (Sievers*) (Udomprasert*) (Yamasaki) NRAO: Myers CITA: Bond Contaldi (Pen) Pogosyan (Prunet) U. de Chile: Achermann* (Altamirano) Bronfman Casassus May Oyarce Chicago: Carlstrom Kovac* Leitch Pryke Berkeley: (Halverson*) (Holzapfel) MSFC: (Joy) U. de Concepcion Bustos* Reeves* Torres * students altitude 16,800 feet

4. Polarization Observations Pablo Altamirano, Ricardo Bustos, John Kovac Rodrigo Reeves, Cristobal Achermann

6. APEX CBI, 5080 m

7. CBI Configuration for Polarization Observations Very close to a perfect matched filter to the expected polarization signal 1 meter LCP RCP vl ul

8. p/2 _i e cmb temperature variations DT(x) to celestial signal D sin q =l u.x q D cos q D=ul E2(t) E1(t) complex correlator Re Im V(u)

9. North . e2piu x -U U Q -Q CBI: 78 baselines 10 frequency channels = 780 separate interferometers Thomson scattering gives rise to E-mode (curl-free) polarization (~10 % of DT) Gravitational waves and lensing also give rise to B-mode polarization (<1 % of DT)

10. Page et al. ApJ 2003, 148, 39 CBI Flux Density scale is tied to the WMAP Flux Density scale, absolute uncertainty = 1.3%

11. Silk damping

17. CBI Polarization EE Observations

19. strategy: size of mosaics chosen so that at the end of 3-4 years the cosmic variance will equal the thermal noise in the center of the CBI l-range

21. If point sources were a factor we would see a l(l +1)xCl dependence in both EE and BB

22. simulations with realistic point source contributions show that the first two bins are expected to change by < 4 mK2

23. 2.1-s 3.4-s 1.6-s significance of shaped fit is 8.9-s without point source projection, or 7.0-s with point source projection

24. CBI EE Polarization Phase • Parameterization 1: envelope plus shiftable sinusoid • fit to “WMAP+ext” fiducial spectrum using rational functions

25. slice at: a=1 =25°±33° rel. phase 7.0-s to 8.9-s detection in amplitude of EE-mode polarization and 3-s rejection of “in phase” EE-TT spectra

26. Example: Acoustic Overtone Pattern • Sound crossing angular size at photon decoupling • Overtone pattern • TT extrema spaced at j intervals • EE spaced at j+1/2 (plus corrections)

27. CBI EE Polarization Phase • Parameterization 2: • Scaling model: spectrum shifts by scaling l • allow amplitude a and scale lto vary best fit: a=0.93 slice along a=1: /0=1.02±0.04 (Dc2=1)

28. overtone 0.67 island: a=0.69±0.03 excluded by TT and other priors other overtone islands also excluded • Scaling model: spectrum shifts by scaling l • allow amplitude a and scale lto vary

29. a=0.5, 0.67 overtone islands: suppressed by DASI DASI phase lock: /0=0.94±0.06 a=0.5 (low DASI) • DASI EE 5-bin bandpowers (Leitch et al. 2004) • bin-bin covariance matrix plus approximate window functions

30. CBI a=0.67 overtone island: suppressed by DASI data CBI+DASI phase lock: /0=1.00±0.03 a=0.78±0.15 (low DASI) other overtone islands also excluded

32. slice at: a=1 =25°±33° rel. phase 7.0-s to 8.9-s detection in amplitude of EE-mode polarization and 3-s rejection of “in phase” EE-TT spectra a marginal result? I don’t think so! apples & oranges: known uncertainties vs.blue-sky predictions of new technologies

33. x a b y polarizers Ga Ea2 Gb Eb2 Ex Ey OMT ± Polarimetry Techniques Ex ~Ea+Eb Ey ~Ea - Eb Gx Gy (ExEy) ~ Gx Gy (Ea2-Eb2 ) Differencing Bolometers Correlation Polarimetry

36. WMAP BICEP QUIET1 QUEST (QUaD) Planck QUIET2 synchrotron 100 GHz synchrotron 100 GHz dust 100 GHz dust 100 GHz Hivon