IsochronePotential¶
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class
gala.potential.
IsochronePotential
(m, b, units)¶ Bases:
gala.potential.CPotentialBase
The Isochrone potential.
\[\Phi = -\frac{GM}{\sqrt{r^2+b^2} + b}\]Parameters: m : numeric
Mass.
b : numeric
Core concentration.
units :
UnitSystem
(optional)Set of non-reducable units that specify (at minimum) the length, mass, time, and angle units.
Methods Summary
action_angle
Transform the input cartesian position and velocity to action-angle coordinates the Isochrone potential. Methods Documentation
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action_angle
()¶ Transform the input cartesian position and velocity to action-angle coordinates the Isochrone potential. See Section 3.5.2 in Binney & Tremaine (2008), and be aware of the errata entry for Eq. 3.225.
This transformation is analytic and can be used as a “toy potential” in the Sanders & Binney 2014 formalism for computing action-angle coordinates in _any_ potential.
Adapted from Jason Sanders’ code here.
Parameters: w :
gala.dynamics.CartesianPhaseSpacePosition
,gala.dynamics.CartesianOrbit
The positions or orbit to compute the actions, angles, and frequencies at.
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