Preprint typeset using L ATEX style emulateapj v. 14/09/00 DETECTION OF POLARIZATION IN THE COSMIC MICROWAVE BACKGROUND USING DASI

• Main Authors: J. Kovac, E. M. Leitch, C. Pryke, J. E. Carlstrom, N. W. Halverson, W. L. Holzapfel
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2008
• Subjects: Amundsen-Scott; South Pole; South pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.4963; http://arxiv.org/pdf/astro-ph/0209478v1.pdf

We report the detection of polarized anisotropy in the Cosmic Microwave Background radiation with the Degree Angular Scale Interferometer (DASI), located at the Amundsen-Scott South Pole research station. Observations in all four Stokes parameters were obtained within two 3. ◦ 4 FWHM fields separated by one hour in Right Ascension. The fields were selected from the subset of fields observed with DASI in 2000 in which no point sources were detected and are located in regions of low Galactic synchrotron and dust emission. The temperature angular power spectrum is consistent with previous measurements and its measured frequency spectral index is −0.01 (−0.16 – 0.14 at 68 % confidence), where 0 corresponds to a 2.73 K Planck spectrum. The power spectrum of the detected polarization is consistent with theoretical predictions based on the interpretation of CMB anisotropy as arising from primordial scalar adiabatic fluctuations. Specifically, E-mode polarization is detected at high confidence (4.9σ). Assuming a shape for the power spectrum consistent with previous temperature measurements, the level found for the E-mode polarization is 0.80 (0.56 – 1.10), where the predicted level given previous temperature data is 0.9 – 1.1. At 95 % confidence, an upper limit of 0.59 is set to the level of B-mode polarization with the same shape and normalization as the E-mode spectrum. The TE correlation of the temperature and