Large scale structured magnetic field of Galaxy Clusters
This module implements the magnetic field derived by [Gourgouliatos2010] as a solution to the Grad-Shafranov equation.
The field strength vanishes on the cavity surface whose interior is otherwise filled by a large scale magnetic field.
Field components are given in spherical coordinates. All components can be accessed with
gammaALPs.bfields.struc.structured_field.b_r()
,
gammaALPs.bfields.struc.structured_field.b_theta()
and
gammaALPs.bfields.struc.structured_field.b_phi()
.
The user is able to set an orientation of the field’s symmetry axis using \(\theta\) (inclination to the line of sight) and \(\mathrm{pa}\) (position angle of jet axis) in galactic coordinates (zero points to Galactic North).
There is also a convenience functions to calculate the the rotation measure induced by the field (provided that an electron density is provided as well).
Reference / API
- class gammaALPs.bfields.struc.structured_field(B0, R, theta, theta_rad, pa, pa_rad, cell_num=1000)[source]
Bases:
object
Class definition of structured magnetic field, see 1008.5353 and 1908.03084 for details.
- F_0 = 182.66504956621472
- __init__(B0, R, theta, theta_rad, pa, pa_rad, cell_num=1000)[source]
Initializes structured B field model. Default values are reasonable for galaxy clusters.
- Parameters:
B0 (float) – Total B field strength at cluster center r=0.
R (float) – Cavity radius, B field goes to zero at r=R.
theta (float) – inclination of symmetry axis w.r.t. line of sight.
theta_rad (bool) – True if theta given in radians.
pa (float) – Position angle of symmetry axis in galactic coordinates.
pa_rad (bool) – True if pa given in radians.
cell_num (int) – Number of cells B field is divided into for propagation of polarization density matrix.
- alpha = 5.7634591968
- property angle
- property b_par
- property b_phi
- property b_r
- property b_theta
- property b_trans
- property dL_vec
- norm = 138.62979162824598
- property r
r needs to be rescaled in field strength expressions to be smaller than one, for “external” use _r is multiplied by R in this property wrapper.
- property rbounds