Cross-correlation of the CMB and foregrounds phases derived from the WMAP data

Abstract

We present circular and linear cross-correlation tests and the "friend-of-friend" analysis for phases of the Internal Linear Combination Map (ILC) and the WMAP foregrounds for all K--W frequency bands at the range of multipoles $\ell\le100$. We compare also Tegmark, de Oliveira-Costa and Hamilton (2003) and Naselsky et al. (2003) cleaned maps with corresponding foregrounds. We have found significant deviations from the expected Poissonian statistics for all the cleaned maps and foregrounds. Our analysis shows that, for a low multipole range of the cleaned maps, power spectra contains some of the foregrounds residuals mainly from the W band.