Improved Measurements of the Temperature and Polarization of the Cosmic Microwave Background from QUaD
Abstract
We present an improved analysis of the final data set from the QUaD experiment. Using an improved technique to remove ground contamination, we double the effective sky area and hence increase the precision of our cosmic microwave background (CMB) power spectrum measurements by ~30% versus that previously reported. In addition, we have improved our modeling of the instrument beams and have reduced our absolute calibration uncertainty from 5% to 3.5% in temperature. The robustness of our results is confirmed through extensive jackknife tests, and by way of the agreement that we find between our two fully independent analysis pipelines. For the standard sixparameter ΛCDM model, the addition of QUaD data marginally improves the constraints on a number of cosmological parameters over those obtained from the WMAP experiment alone. The impact of QUaD data is significantly greater for a model extended to include either a running in the scalar spectral index, or a possible tensor component, or both. Adding both the QUaD data and the results from the Arcminute Cosmology Bolometer Array Receiver experiment, the uncertainty in the spectral index running is reduced by ~25% compared to WMAP alone, while the upper limit on the tensortoscalar ratio is reduced from r < 0.48 to r < 0.33 (95% c.l.). This is the strongest limit on tensors to date from the CMB alone. We also use our polarization measurements to place constraints on parityviolating interactions to the surface of last scattering, constraining the energy scale of Lorentz violating interactions to <1.5 × 10^{43} GeV (68% c.l.). Finally, we place a robust upper limit on the strength of the lensing Bmode signal. Assuming a single flat band power between ell = 200 and ell = 2000, we constrain the amplitude of Bmodes to be <0.57 μK^{2} (95% c.l.).
 Publication:

The Astrophysical Journal
 Pub Date:
 November 2009
 DOI:
 10.1088/0004637X/705/1/978
 arXiv:
 arXiv:0906.1003
 Bibcode:
 2009ApJ...705..978B
 Keywords:

 cosmic microwave background;
 cosmological parameters;
 cosmology: observations;
 polarization;
 Astrophysics  Cosmology and Extragalactic Astrophysics
 EPrint:
 23 pages, 19 figures, updated to reflect published version