A note on the large-angle anisotropies in the WMAP cut-sky maps
Abstract
Recent analyses of the WMAP data seem to indicate the possible presence of large-angle anisotropy in the Universe. If confirmed, these can have important consequences for our understanding of the Universe. A number of attempts have recently been made to establish the reality and nature of such anisotropies in the CMB data. Among these is a directional indicator recently proposed by the authors. A distinctive feature of this indicator is that it can be used to generate a sky map of the large-scale anisotropies of the CMB maps. Applying this indicator to full-sky temperature maps we found a statistically significant preferred direction. The full-sky maps used in these analyses are known to have residual foreground contamination as well as complicated noise properties. Thus, here we performed the same analysis for a map where regions with high foreground contamination were removed. We find that the main feature of the full-sky analysis, namely the presence of a significant axis of asymmetry, is robust with respect to this masking procedure. Other subtler anomalies of the full-sky are on the other hand no longer present.
Cite
@article{arxiv.0706.0575,
title = {A note on the large-angle anisotropies in the WMAP cut-sky maps},
author = {A. Bernui and B. Mota and M. J. Reboucas and R. Tavakol},
journal= {arXiv preprint arXiv:0706.0575},
year = {2009}
}