Moving object potential

class galpy.potential.MovingObjectPotential(orbit, amp=1.0, GM=0.06, softening=None, softening_model='plummer', softening_length=0.01)

Class that implements the potential coming from a moving object

\[\Phi(R,z,\phi,t) = -\mathrm{amp}\,GM\,S(d)\]

where \(d\) is the distance between \((R,z,\phi)\) and the moving object at time \(t\) and \(S(\cdot)\) is a softening kernel. In the case of Plummer softening, this kernel is

\[S(d) = \frac{1}{\sqrt{d^2+\mathrm{softening\_length}^2}}\]

Plummer is currently the only implemented softening.

__init__(orbit, amp=1.0, GM=0.06, softening=None, softening_model='plummer', softening_length=0.01)

NAME:

__init__

PURPOSE:

initialize a MovingObjectPotential

INPUT:

orbit - the Orbit of the object (Orbit object)

amp= - amplitude to be applied to the potential (default: 1)

GM - ‘mass’ of the object (degenerate with amp)

Softening: either provide

1. softening= with a ForceSoftening-type object

2. softening_model= type of softening to use (‘plummer’)

   softening_length= (optional)

OUTPUT:

(none)

HISTORY:

2011-04-10 - Started - Bovy (NYU)