Search

It has been pointed out that the spurious cosmic microwave background (CMB) B -mode polarization signals caused by the absorption of the CMB monopole component due to the Galactic interstellar matter, called the CMB shadow, degrade the accuracy of detecting the CMB B -mode polarization signals imprinted by primordial gravitational waves. We have made a realistic estimation using simulated sky maps of how the CMB shadow affects forthcoming high-precision CMB B -mode experiments for the first time. The delta-map method, an internal template method taking into account the first-order spatial variation of foregrounds’ spectral parameters, is applied as a foreground-removal method. We show that if the CMB shadow effects are not taken into account in the foreground-removal process, future observations would lead to the false detection of the CMB B -mode polarization signals originating from primordial gravitational waves. We also show that the effect of the CMB shadow can be mitigated by our revised delta-map method to target the CMB B -mode polarization signals at the level of tensor-to-scalar ratio r = 0.001.

We present a far-infrared all-sky atlas from a sensitive all-sky survey using the Japanese AKARI satellite. The survey covers >99% of the sky in four photometric bands centred at 65 μm, 90 μm, 140 μm, and 160 μm, with spatial resolutions ranging from 1' to 1."5. These data provide crucial information on the investigation and characterisation of the properties of dusty material in the interstellar medium (ISM), since a significant portion of its energy is emitted between ~50 and 200 μm. The large-scale distribution of interstellar clouds, their thermal dust temperatures, and their column densities can be investigated with the improved spatial resolution compared to earlier all-sky survey observations. In addition to the point source distribution, the large-scale distribution of ISM cirrus emission, and its filamentary structure, are well traced. We have made the first public release of the full-sky data to provide a legacy data set for use in the astronomical community. [ABSTRACT FROM AUTHOR]