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Abstract: This paper provides full sky maps of foreground emission in all WMAPchannels, with very low residual contamination from the Cosmic MicrowaveBackground CMB anisotropies and controlled level of instrumental noise.Foreground maps are obtained by subtraction of a properly filtered CMB map,obtained from linear combinations of needlet-based representations of all WMAPobservations and of a 100-micron map. The error in the reconstructed foregroundmaps on large scales is significantly lower than the original error due to CMBcontamination, while remaining of the order of the original WMAP noise on smallscales. The level of the noise is estimated, which permits to implement localfilters for maximising the local signal to noise ratio. An example of suchfiltering, which reduces the small scale noise using latitude dependent filtersis implemented. This enhances significantly the contrast of galactic emission,in particular on intermediate angular scales and at intermediate galacticlatitude. The clean WMAP foreground maps can be used to study the galacticinterstellar medium, in particular for the highest frequency channels for whichthe proper subtraction of CMB contamination is mandatory. The foregrounds mapscan be downloaded from a dedicated web site.



Author: Tuhin Ghosh, Jacques Delabrouille, Mathieu Remazeilles, Jean-Francois Cardoso, Tarun Souradeep

Source: https://arxiv.org/







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