Galactic Magnetic Turbulence from Radio data

TL;DR

This paper analyzes radio maps to study Galactic magnetic turbulence, revealing a flatter turbulence spectrum than classical models and suggesting implications for cosmic-ray propagation and magnetic field structure.

Contribution

It provides new constraints on the turbulence spectral index and halo scale from radio data, challenging traditional Kolmogorov turbulence assumptions.

Findings

Flatter turbulence spectral index than Kolmogorov

Evidence for a thin Galactic halo

Implications for cosmic-ray propagation models

Abstract

Fluctuations in the Galactic synchrotron emission can be traced by the angular power spectrum of radio maps at low multipoles. At frequencies below few GHz, large-scale anisotropies are mainly induced by magnetic field turbulence. By performing an analysis of five radio maps, we extract constraints on turbulence spectral index and halo scale. Results favour a power spectrum significantly flatter than for 3D Kolmogorov-like turbulence, and a thin halo. This can be interpreted as an indication supporting non-conventional models of propagation of cosmic-ray particles in the Galaxy, or as a suggestion of a spectral-index break in the observed magnetic turbulence power spectrum.