Double power-law density spherical potential

class galpy.potential.TwoPowerSphericalPotential(amp=1.0, a=5.0, alpha=1.5, beta=3.5, normalize=False)

Class that implements spherical potentials that are derived from two-power density models

\[\rho(r) = \frac{\mathrm{amp}}{4\,\pi\,a^3}\,\frac{1}{(r/a)^\alpha\,(1+r/a)^{\beta-\alpha}}\]

__init__(amp=1.0, a=5.0, alpha=1.5, beta=3.5, normalize=False)

NAME:

__init__

PURPOSE:

initialize a two-power-density potential

INPUT:

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

a - “scale” (in terms of Ro)

alpha - inner power

beta - outer power

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.

OUTPUT:

(none)

HISTORY:

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