# Hernquist potential¶

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

Class that implements the Hernquist potential

$\rho(r) = \frac{\mathrm{amp}}{4\,\pi\,a^3}\,\frac{1}{(r/a)\,(1+r/a)^{3}}$
__init__(amp=1.0, a=1.0, normalize=False, ro=None, vo=None)[source]

NAME:

__init__

PURPOSE:

Initialize a Hernquist potential

INPUT:

amp - amplitude to be applied to the potential (default: 1); can be a Quantity with units of mass or Gxmass (note that amp is 2 x [total mass] for the chosen definition of the Hernquist potential)

a - scale radius (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 - Written - Bovy (NYU)