Magnetic field of Galaxy clusters with Gaussian Turbulence

This module implements a divergence-free homogeneous and isotropic Gaussian turbulent magnetic field with zero mean and variance \(\mathcal{B}^2\) as described in detail in [Meyer2014] and also used, e.g., in [Ajello2016]. The power spectrum of the turbulence follows a power law in terms of wave numbers \(k\),

\[M(k) \propto k^q\]

between \(k_L \leqslant k \leqslant k_H\) and zero otherwise.

The Fourier transform of the correlation function of the transversal B-field components is

\[\tilde\epsilon_\perp(k) = \frac{\pi\mathcal{B}^2}{4} F_q(k ; k_L, k_H),\]

where the function \(F_q(k; k_L,k_H)\) is defined in the appendix of [Meyer2014].

A new single realization of the magnetic field along the line of sight is computed with gammaALPs.bfields.gauss.Bgaussian.Bgaus and the transversal component (relevant to photon-ALP mixing) for potentially many realizations is calculated with gammaALPs.bfields.gauss.Bgaussian.new_Bn(). There are also two convenience functions to calculate the spatial correlation and the the rotation measure induced by the field (provided that an electron density is provided as well).

Reference / API