Double power-law density spherical potential¶
- class galpy.potential.TwoPowerSphericalPotential(amp=1.0, a=5.0, alpha=1.5, beta=3.5, normalize=False, ro=None, vo=None)[source]¶
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, ro=None, vo=None)[source]¶
NAME:
__init__
PURPOSE:
initialize a two-power-density potential
INPUT:
amp - amplitude to be applied to the potential (default: 1); can be a Quantity with units of mass or Gxmass
a - scale radius (can be Quantity)
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.
ro=, vo= distance and velocity scales for translation into internal units (default from configuration file)
OUTPUT:
(none)
HISTORY:
2010-07-09 - Started - Bovy (NYU)