Scientific optimization of a ground-based CMB polarization experiment

• Main Authors: Bowden, M., Taylor, A. N., Ganga, K. M., Ade, P. A. R., Bock, J. J., Cahill, G., Carlstrom, J. E., Church, S. E., Gear, W. K., Hinderks, J. R., Hu, W., Keating, B. G., Kovac, J., Lange, A . E., Leitch, E. M., Mallie, O. E., Melhuish, S. J., Murphy, J. A., Piccirillo, L., Pryke, C., Rusholme, B. A., O'Sullivan, C., Thompson, K.
• Format: Text
• Language: unknown
• Published: arXiv 2003
• Subjects: Astrophysics astro-ph; FOS Physical sciences; South Pole; South pole
• Online Access: https://dx.doi.org/10.48550/arxiv.astro-ph/0309610; https://arxiv.org/abs/astro-ph/0309610

We investigate the science goals achievable with the upcoming generation of ground-based Cosmic Microwave Background polarization experiments and calculate the optimal sky coverage for such an experiment including the effects of foregrounds. We find that with current technology an E-mode measurement will be sample-limited, while a B-mode measurement will be detector-noise-limited. We conclude that a 300 sq deg survey is an optimal compromise for a two-year experiment to measure both E and B-modes, and that ground-based polarization experiments can make an important contribution to B-mode surveys. Focusing on one particular experiment, QUaD, a proposed bolometric polarimeter operating from the South Pole, we find that a ground-based experiment can make a high significance measurement of the acoustic peaks in the E-mode spectrum, and will be able to detect the gravitational lensing signal in the B-mode spectrum. Such an experiment could also directly detect the gravitational wave component of the B-mode spectrum if the amplitude of the signal is close to current upper limits. We also investigate how a ground-based experiment can improve constraints on the cosmological parameters. We estimate that by combining two years of QUaD data with the four-year WMAP data, an optimized ground-based polarization experiment can improve constraints on cosmological parameters by a factor of two. If the foreground contamination can be reduced, the measurement of the tensor-to-scalar ratio can be improved by up to a factor of six over that obtainable from WMAP alone. : 17 pages, 11 figures replaced with version accepted by MNRAS