A needlet ILC analysis of WMAP 7-year data: estimation of CMB temperature map and power spectrum

Understand

The WMAP 7-year temperature maps have been re-analized to extract a CMB map and CMB power spectrum with reduced contamination by astrophysical foregrounds and noise.

• The method used is based on linear combinations of WMAP data and foreground templates, implemented on a decomposition of the observations onto a needlet frame.
• We obtain a clean CMB map with low contamination from foregrounds and noise, as well as a new estimate of the CMB temperature power spectrum.
• The latter is essentially compatible with the power spectrum published by the WMAP collaboration, although it is slightly but systematically lower on large scales.