Preprint typeset using LATEX style emulateapj v. 10/09/06 MEASUREMENT OF CMB POLARIZATION POWER SPECTRA FROM TWO YEARS OF BICEP DATA

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2009
• Subjects: South Pole; South pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.249.4006; http://arxiv.org/pdf/0906.1181v1.pdf

BICEP is a bolometric polarimeter designed to measure the inflationary B-mode polarization of the cosmic microwave background (CMB) at degree angular scales. During three seasons of observing at the South Pole (2006 through 2008), BICEP mapped ∼ 2 % of the sky chosen to be uniquely clean of polarized foreground emission. Here we present initial results derived from a subset of the data acquired during the first two years. We present maps of temperature, Stokes Q and U, E and B modes, and associated angular power spectra. We demonstrate that the polarization data are self-consistent by performing a series of jackknife tests. We study potential systematic errors in detail and show that they are sub-dominant to the statistical errors. We measure the E-mode angular power spectrum with high precision at 21 ≤ ℓ ≤ 335, detecting for the first time the peak expected at ℓ ∼ 140. The measured E-mode spectrum is consistent with expectations from a ΛCDM model, and the B-mode spectrum is consistent with zero. The tensor-to-scalar ratio derived from the B-mode spectrum is r = 0.03 +0.31 −0.27, or r < 0.73 at 95 % confidence, the first meaningful constraint on the inflationary gravitational wave background to come directly from CMB B-mode polarization. Subject headings: cosmic microwave background polarization, cosmology, inflation, bolometers 1.