SIMPLE FOREGROUND CLEANING ALGORITHM FOR DETECTING PRIMORDIAL B-MODE POLARIZATION OF THE COSMIC MICROWAVE BACKGROUND
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization and School of High Energy Accelerator Science, Graduate University for Advanced Studies (Sokendai), Tsukuba, Ibaraki 305-0801 (Japan)
- Texas Cosmology Center and Department of Astronomy, University of Texas, Austin, TX (United States)
We reconsider the pixel-based, 'template' polarized foreground removal method within the context of a next-generation, low-noise, low-resolution (0.{sup 0}5 FWHM) space-borne experiment measuring the cosmological B-mode polarization signal in the cosmic microwave background (CMB). This method was first applied to polarized data by the Wilkinson Microwave Anisotropy Probe (WMAP) team and further studied by Efstathiou et al. We need at least three frequency channels: one is used for extracting the CMB signal, whereas the other two are used to estimate the spatial distribution of the polarized dust and synchrotron emission. No extra data from non-CMB experiments or models are used. We extract the tensor-to-scalar ratio (r) from simulated sky maps outside the standard polarization mask (P06) of WMAP consisting of CMB, noise (2 {mu}K arcmin), and a foreground model, and find that, even for the simplest three-frequency configuration with 60, 100, and 240 GHz, the residual bias in r is as small as {Delta}r {approx} 0.002. This bias is dominated by the residual synchrotron emission due to spatial variations of the synchrotron spectral index. With an extended mask with f{sub sky} = 0.5, the bias is reduced further down to <0.001.
- OSTI ID:
- 21579921
- Journal Information:
- Astrophysical Journal, Vol. 737, Issue 2; Other Information: DOI: 10.1088/0004-637X/737/2/78; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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