Galactic foreground and CMB emissions randomization due to chaotic/turbulent dynamics of magnetized plasma dominated by magnetic helicity

TL;DR

This paper demonstrates that Galactic foreground emissions become increasingly randomized at higher frequencies due to turbulent magnetized plasma dynamics, with magnetic helicity playing a key role, supported by simulations and observations.

Contribution

It introduces a novel analysis linking magnetic helicity-driven turbulence to frequency-dependent randomization of Galactic emissions, validated by both simulations and astrophysical data.

Findings

Foreground emission randomization increases with frequency

Magnetic field influences synchrotron and dust emission levels

Background magnetic fields are less randomized than foreground emissions

Abstract

Using results of numerical simulations and astrophysical observations (mainly in the WMAP and Planck frequency bands) it is shown that Galactic foreground emission becomes more sensitive to the mean magnetic field with the frequency, that results in the appearance of two levels of its randomization due to chaotic/turbulent dynamics of magnetized interstellar medium dominated by the magnetic helicity. The galactic foreground emission is more randomized at higher frequencies. The Galactic synchrotron and polarized dust emissions have been studied in detail. It is shown that the magnetic field imposes its level of randomization on the synchrotron and dust emission. The background magnetic field (around the lepto/baryogenesis) and CMB emission have also been briefly discussed in this context. It is shown that they are considerably less randomized than the foreground ones. The main method for the theoretical consideration used in this study is the Kolmogorov-Iroshnikov phenomenology within the framework of the distributed chaos notion. Despite the vast differences in the values of physical parameters and spatio-temporal scales between the numerical simulations and the astrophysical observations, there is a quantitative agreement between the results of the astrophysical observations and the numerical simulations within the framework of the distributed chaos notion.