Spectral Properties of Background Signal Peaks at Medium and High Multipoles

Abstract

The spectral properties of inhomogeneities of the cosmic microwave background are considered. The inhomogeneity spectra are studied in the frequency range from 30 to 217 GHz according to multi-frequency maps of the Planck space mission with smoothing at different angular sizes. According to the thermodynamic temperature versus frequency relation, it is shown that the map at 70 GHz has a signal distribution that differs from the data at other frequencies depending on the smoothing window. At 70 GHz, there is a peak in the spectrum, most strongly manifested on maps without smoothing. In the inhomogeneity spectra represented by the frequency dependence of the flux density for data at high multipoles (ℓ > 200, θ < 30'), the signal behavior different from the low multipoles (ℓ < 200) was found, which demonstrates a monotonically growing spectrum with an increase in frequency from 30 to 217 GHz.