The problem of Galactic foreground in CMB observations
After the great success of WMAP and Planck space missions, Cosmic Microwave Background (CMB) observations have now entered the era of B-modes measurements. The challenge, for current and future generation of CMB experiments, is the detection of the B-mode signal at degree angular scales. This represents, indeed, the smoking gun of the existence of cosmological gravitational waves generated by quantum fluctuations of spacetime stretched at cosmological scales by Inflation. To achieve this goal not only exquisite sensitivity is needed but also high control of the bright non-cosmological polarized emissions, dominating over the CMB B-modes all over the sky.
In this talk I will present recent results about the characterization of Galactic polarized signals. For what concern thermal dust emission I will briefly review the latest results obtained from the Planck high frequency observations (https://arxiv.org/abs/1801.04945). Moreover, I will present the recent analysis of S-PASS data at 2.3 GHz (https://arxiv.org/abs/1802.01145). The S-PASS survey covered 50% of the sky (Southern Hemisphere) and observed the polarized synchrotron with unprecedented sensitivity and angular resolution. The results include the characterization of synchrotron angular power spectrum, the measurement of the spectral energy distribution and of the correlation between synchrotron and thermal dust emissions. All this results represent an important step forward in our knowledge of the foreground emission, essential to isolate the CMB B-mode signal.