Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Improved measurements of the temperature and polarization of the cosmic microwave background from QUaD

Brown, M. L., Ade, Peter A. R., Bock, J., Bowden, Melanie, Cahill, G., Castro, P. G., Church, S., Culverhouse, T., Friedman, R. B., Ganga, K., Gear, Walter Kieran, Gupta, Sujata, Hinderks, J., Kovac, J., Lange, A. E., Leitch, E., Melhuish, Simon John, Memari, Y., Murphy, J. A., Orlando, Angiola, O'Sullivan, C., Piccirillo, Lucio, Pryke, C., Rajguru, Nutan J., Rusholme, B., Schwarz, R., Taylor, A. N., Thompson, K. L., Turner, Abigail Helen, Wu, E. Y. S. and Zemcov, Michael 2009. Improved measurements of the temperature and polarization of the cosmic microwave background from QUaD. Astrophysical Journal 705 (1) , pp. 978-999. 10.1088/0004-637X/705/1/978

Full text not available from this repository.


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 six-parameter 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 tensor-to-scalar 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 parity-violating 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 B-mode signal. Assuming a single flat band power between = 200 and = 2000, we constrain the amplitude of B-modes to be <0.57 μK2 (95% c.l.).

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Uncontrolled Keywords: Cosmic microwave background ; Cosmological parameters ; Cosmology: observations ; Polarization
Publisher: Institute of Physics
ISSN: 0004-637X
Last Modified: 03 Feb 2020 00:24

Citation Data

Cited 325 times in Google Scholar. View in Google Scholar

Cited 216 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item