Comparison of low-harmonics spectra and maps according to the WMAP and Planck space missions

Abstract

We present a comparison of the angular power spectra and maps represented by the WMAP and Planck mission teams. The spectra are compared in the the multi pole range (2 ≤ ℓ ≤ 50). The ℓ =5, 7, 13, 29, 37, 41–46 harmonics have a discrepancy in the angular power spectra. The maps of the microwave background and their phase characteristics are studied at these spatial frequencies. We show that the discrepancy of the spectra is due to a different account of the systematics linked with the Galaxy, the ecliptic, and possibly with the Earth. These effects, leading to a statistical anisotropy, may be responsible for the observed anomalies in both experiments at low harmonics.