Implemented Astrophysical Environments

This page summarizes the available astrophysical environments in which the photon-ALP propagation can be calculated. The environments can be added to the propagation by invoking the add_propagation() function, see the Core Modules page for more information, as well as the Tutorials.

The astrophysical environments combine the magnetic field models (see Magnetic Field Models) and models for the electron density \(n_\mathrm{el}(r)\) (see Electron Density Models) and are summarized in the table below.

A minimal example for initializing mixing in the intergalactic magnetic field (IGMF) would like this:

from gammaALPs.core import Source, ALP, ModuleList
src = Source(z=0.536)  # initialize a source with redshift z=0.536
alp = ALP(m=1., g=1.)
ml = ModuleList(alp, src)
ml.add_propagaion('IGMF')
px, py, pa = ml.run()

The other supported environments are listed in the table below.

Environment Name	Environment Class	Intended Use	Used \(B\)-field model	Used \(n_\mathrm{el}\) model
IGMF	`MixIGMFCell`	Mixing in the intergalactic magnetic field with a cell-like structure	`Bcell`	constant (evolves with redshift)
ICMCell	`MixICMCell`	Mixing in a galaxy cluster magnetic field with a cell-like structure that decreases with growing distance from cluster center following \(n_\mathrm{el}(r)\)	`Bcell`	`NelICM`
ICMGaussTurb	`MixICMGaussTurb`	Mixing in a galaxy cluster magnetic field with Gaussian turbulence that decreases with growing distance from cluster center following \(n_\mathrm{el}(r)\)	`Bgaussian`	`NelICM`
ICMStructured	`MixICMStructured`	Mixing in an intra-cluster cavity field.	:py:class:`~gammaALPs.bfields.struc.structured_field	`NelICM`
Jet	`MixJet`	Mixing in the toroidal magnet field of an AGN jet, where the B field and \(n_\mathrm{el}(r)\) decrease as a power law with increasing distance from the central supermassive black hole	`Bjet`	`NelJet`
JetHelicalTangled	`MixJetHelicalTangled`	Mixing in helical and tangled field of an AGN jet, where the B field and \(n_\mathrm{el}(r)\) decrease as a power law with increasing distance from the central supermassive black hole.	`BjetHelicalTangled`	`NelJetHelicalTangled`
GMF	`MixGMF`	Mixing in the magnetic field of the Milky Way. Currently, no model for \(n_\mathrm{el}\) is implemented	`GMF` `GMFPshirkov` `UF23`	constant
File	`MixFromFile`	Environment initalized from B field and \(n_\mathrm{el}\) from a file	—	—
Array	`MixFromArray`	Environment initalized from B field and \(n_\mathrm{el}\) from numpy arrays	—	—
EBL	`OptDepth`	No mixing, only absorption on the EBL	—	—

Implemented Astrophysical Environments

Reference / API