Double exponential disk potential

class galpy.potential.DoubleExponentialDiskPotential(amp=1.0, hr=0.3333333333333333, hz=0.0625, normalize=False, ro=None, vo=None, de_h=0.001, de_n=10000)[source]

Class that implements the double exponential disk potential

\[\rho(R,z) = \mathrm{amp}\,\exp\left(-R/h_R-|z|/h_z\right)\]
__init__(amp=1.0, hr=0.3333333333333333, hz=0.0625, normalize=False, ro=None, vo=None, de_h=0.001, de_n=10000)[source]

Initialize a double exponential disk potential

Parameters:
  • amp (float or Quantity, optional) – Amplitude to be applied to the potential (default: 1); can be a Quantity with units of mass density or Gxmass density.

  • hr (float or Quantity, optional) – Disk scale-length.

  • hz (float or Quantity, optional) – Scale-height.

  • normalize (bool or float, optional) – 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.

  • de_h (float, optional) – Step used in numerical integration.

  • de_n (int, optional) – Number of points used in numerical integration (use 1000 for a lower accuracy version that is typically still high accuracy enough, but faster).

  • ro (float, optional) – Distance scale for translation into internal units (default from configuration file).

  • vo (float, optional) – Velocity scale for translation into internal units (default from configuration file).

Notes

  • 2010-04-16 - Written - Bovy (NYU)

  • 2013-01-01 - Re-implemented using faster integration techniques - Bovy (IAS)

  • 2020-12-24 - Re-implemented again using more accurate integration techniques for Bessel integrals - Bovy (UofT)