Turbulent axion-photon conversions in the Milky-Way

TL;DR

This paper examines how the turbulent magnetic field in the Milky Way influences axion-photon conversions, revealing it can significantly alter probabilities and produce observable spectral irregularities.

Contribution

It introduces a detailed analysis of the turbulent magnetic field's impact on ALP-photon conversions, extending previous models that only considered regular magnetic fields.

Findings

Turbulent magnetic fields can double the conversion probability.

Turbulence causes observable irregularities in photon spectra.

Impact varies depending on astrophysical source characteristics.

Abstract

The Milky-Way magnetic field can trigger conversions between photons and axion-like particles (ALPs), leading to peculiar features on the observable photon spectra. Previous studies considered only the regular component of the magnetic field. However, observations consistently show the existence of an additional turbulent component, with a similar strength and correlated on a scale of a few 10$\,$pc. We investigate the impact of the turbulent magnetic field on the ALP-photon conversions, characterizing the effects numerically and analytically. We show that the turbulent magnetic field can change the conversion probability by up to a factor of two and may lead to observable irregularities in the observable photon spectra from different astrophysical sources.