Miyamoto-Nagai potential

class galpy.potential.MiyamotoNagaiPotential(amp=1.0, a=1.0, b=0.1, normalize=False, ro=None, vo=None)[source]

Class that implements the Miyamoto-Nagai potential

\[\Phi(R,z) = -\frac{\mathrm{amp}}{\sqrt{R^2+(a+\sqrt{z^2+b^2})^2}}\]

with \(\mathrm{amp} = GM\) the total mass.

__init__(amp=1.0, a=1.0, b=0.1, normalize=False, ro=None, vo=None)[source]

NAME:

__init__

PURPOSE:

initialize a Miyamoto-Nagai potential

INPUT:

amp - amplitude to be applied to the potential, the total mass (default: 1); can be a Quantity with units of mass or Gxmass

a - scale length (can be Quantity)

b - scale height (can be Quantity)

normalize - if True, normalize such that vc(1.,0.)=1., or, if given as a number, such that the force is this fraction of the force necessary to make vc(1.,0.)=1.

ro=, vo= distance and velocity scales for translation into internal units (default from configuration file)

OUTPUT:

(none)

HISTORY:

2010-07-09 - Started - Bovy (NYU)