Multi-frequency observations are needed to separate the CMB from foregrounds and accurately extract cosmological information from the data. In the past decades, many ground-based, balloon- borne and satellite experiments have been dedicated to CMB observations. The latest results from the Planck satellite achieved a precise measurement not only for temperature anisotropies, but also for CMB polarization E- modes. As an outcome of these experiments, much cosmological information has already been extracted from the CMB. Recently, much attention has been focused on the CMB polarization anisotropies, especially the B-modes, which are of particular interest as they are expected to probe inflation. However, a precise measurement of these B-modes strongly depends on our ability to separate the signal from the astrophysical foregrounds. In this seminar, I will discuss the foreground cleaning performance considering CMB polarization experiments, mainly in the context of the Chinese ground-based Ali CMB Polarization Telescope.
Giancarlo de Gasperis