Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-07-13
Astronomy and Astrophysics
Astrophysics
4 pages, 5 figures, will appear on A&A Lett
Scientific paper
10.1051/0004-6361:20065535
The aim of the present analysis is to improve the knowledge of the statistical properties of the Galactic diffuse synchrotron emission, which constrains sensitive CMB anisotropy measurements. We have analysed the new DRAO 1.4 GHz polarization survey together with the Stockert 1.4 GHz total intensity survey and derived the angular power spectra (APSs) of the total intensity, the polarized emission, and their cross-correlation for the entire surveys and for three low-intensity regions. The APSs of the diffuse synchrotron emission are modelled by power laws. For the $E$ and $B$ modes, a slope of $\alpha \sim [-3.0,-2.5]$ for the multipole range $\sim [30,300]$ is found. By the extrapolation of these results to 70 GHz, we can estimate the Galactic synchrotron contamination of CMB anisotropies, and we find results that are compatible with the ones coming from WMAP 3-yr data. In the low-intensity regions, the cosmological primordial B~mode peak at $\ell \sim 100$ should be clearly observable for a tensor-to-scalar ratio $T/S \gsim 0.5$ and a synchrotron temperature spectral index $\beta \sim -3$. Its detection is also possible for $T/S \gsim 0.005$ and $\beta \sim -3$, in case a separation of the foreground from the CMB signal could be achieved with an accuracy of $\sim 5-10%$. For the TE mode, a mask excluding $|b_{gal}| \le 5^{\circ}$ (for $\beta\sim -3.0$) or $|b_{gal}| \le 20^{\circ}$ (for $\beta\sim -2.8$) from the surveys is sufficient to render the foreground contamination negligible, thus confirming the ability of WMAP to have a clear view of the temperature-polarization correlation peak and antipeak series.
Burigana Carlo
Porta Laura La
Reich Patricia
Reich Wolfgang
No associations
LandOfFree
An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-481510