DF (galpy.df)

galpy.df contains tools for dealing with distribution functions of stars in galaxies. It mainly contains a number of classes that define different types of distribution function, but galpy.df.jeans also has some tools for solving the Jeans equations for equilibrium systems.

Jeans modeling tools (galpy.df.jeans)

General instance routines for all df classes

Spherical distribution functions

Isotropic and anisotropic distribution functions for spherical systems.

General instance routines

Sampling routines

Specific distribution functions

The following are isotropic distribution functions

Anisotropic versions also exist:

Two-dimensional, axisymmetric disk distribution functions

Distribution function for orbits in the plane of a galactic disk.

Specific distribution functions

Two-dimensional, non-axisymmetric disk distribution functions

Distribution function for orbits in the plane of a galactic disk in non-axisymmetric potentials. These are calculated using the technique of Dehnen 2000, where the DF at the current time is obtained as the evolution of an initially-axisymmetric DF at time to in the non-axisymmetric potential until the current time.

Three-dimensional disk distribution functions

Distribution functions for orbits in galactic disks, including the vertical motion for stars reaching large heights above the plane. Currently only the quasi-isothermal DF.

Specific distribution functions

The distribution function of a gap in a tidal stream

From Sanders, Bovy, & Erkal 2015; see Modeling gaps in streams. Implemented as a subclass of streamdf. No full implementation is available currently, but the model can be set up and sampled as in the above paper.

General instance routines