Removing real-world foregrounds from CMB maps
Abstract
Most work on foreground removal has treated the case where the frequency dependence of all components is perfectly known and independent of position. In contrast, real-world foregrounds are generally not perfectly correlated between frequencies, with the spectral index varying slightly with position and (in the case of some radio sources) with time. A method incorporating this complication in presented, and illustrated with an application to the upcoming satellite missions MAP and Planck. We find that even spectral index variations as small as 0.1 can have a substantial impact on how channels should be combined and on attainable accuracy.
Cite
@article{arxiv.astro-ph/9712038,
title = {Removing real-world foregrounds from CMB maps},
author = {Max Tegmark},
journal= {arXiv preprint arXiv:astro-ph/9712038},
year = {2009}
}
Comments
Expanded with wavelet discussion. Matches accepted ApJ version. 6 pages, with 3 figs included. Color figures and links at http://www.sns.ias.edu/~max/foregrounds.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/foregrounds.html (faster from Europe) or from [email protected]