Spherical Tests

These are the simplest tests: a suite of spherical one and two component galaxies. The files are available for download as Gadget format binary files. For information on reading/writing Gadget files, see file formats.

For all tests, the units are:

  • Graph
  • Graph
  • Graph

Single component models

We set up three isotropic single component models described by a simple “Dehnen” split power-law sphere, using the method described in Read et al. 2006:


where Graph is the total mass, Graph is the central asymptotic logarithmic slope, and Graph is the scale length. The parameters and data files are given in the following Table:

where Graph is the number of particles that for these single component models are stored in the dark matter array.

A million sample points is, of course, optimistic, but these can be simply down-sampled to represent a more realistic observational situation. Similarly, line of sight velocities can be used, rather than the full phase space information.

Multi component models

We set up three spherical isotropic multi-component models similarly to the single component models, above. These are double-Dehnen spheres with stars describing a tracer population of negligible mass and dark matter (with a different distribution function) describing the mass distribution. The properties are as follows:

Graph Graph Graph Graph Graph Graph Graph Graph file
1 1 0 Graph Graph 0.1 0 Graph dual_unit_hern_0.gad
1 1 1 Graph Graph 0.1 0 Graph dual_unit_hern_1.gad
1 1 2 Graph Graph 0.1 1 Graph dual_unit_hern_2.gad


Please feel free to discuss/comment on these tests here. You need to log in to contribute.

Recent changes RSS feed Creative Commons License Donate Driven by DokuWiki