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B-mode contamination by synchrotron emission from 3-yr Wilkinson Microwave Anisotropy Probe data.
- Source :
- Monthly Notices of the Royal Astronomical Society: Letters; Nov2006, Vol. 373 Issue 1, pL93-L97, 5p, 1 Chart, 2 Graphs, 1 Map
- Publication Year :
- 2006
-
Abstract
- We study the contamination of the B-mode of the cosmic microwave background polarization (CMBP) by Galactic synchrotron in the lowest emission regions of the sky. The 22.8-GHz polarization map of the 3-yr Wilkinson Microwave Anisotropy Probe ( WMAP) data release is used to identify and analyse such regions. Two areas are selected with signal-to-noise ratio S/N < 2 and S/N < 3, covering ∼16 and ∼26 per cent fraction of the sky, respectively. The polarization power spectra of these two areas are dominated by the sky signal on large angular scales (multipoles ℓ < 15), while the noise prevails on degree scales. Angular extrapolations show that the synchrotron emission competes with the CMBP B-mode signal for tensor-to-scalar perturbation power ratio at 70 GHz in the 16 per cent lowest emission sky (S/N < 2 area). These values worsen by a factor ∼5 in the S/N < 3 region. The novelty is that our estimates regard the whole lowest emission regions and outline a contamination better than that of the whole high Galactic latitude sky found by the WMAP team . Such regions allow to be measured directly which approximately corresponds to the limit imposed by using a sky coverage of 15 per cent. This opens interesting perspectives on the investigation of the inflationary model space in lowest emission regions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 17453925
- Volume :
- 373
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Monthly Notices of the Royal Astronomical Society: Letters
- Publication Type :
- Academic Journal
- Accession number :
- 22978635
- Full Text :
- https://doi.org/10.1111/j.1745-3933.2006.00250.x