Singular isothermal sphere profile

From Wikipedia, the free encyclopedia
Jump to: navigation, search

The singular isothermal sphere (SIS) profile is the simplest parameterization of the spatial distribution of matter in an astronomical system (e.g. galaxies, clusters of galaxies, etc.).[1]

Density distribution[edit]

\rho(r) = \frac{\sigma_{V}^{2}}{2\pi G r^{2}}

where σV2 is the velocity dispersion and G is the gravitational constant. The SIS profile is unphysical because of the singularity at zero radius and the fact that the corresponding SIS mass is infinite. However, it is commonly utilized in the literature due to the simplicity of its form.

See also[edit]


  1. ^ Keeton, C. (June 2002). "A Catalog of Mass Models for Gravitational Lensing". v2. arXiv:astro-ph/0102341 [astro-ph].  Unsupported parameter(s) in cite arXiv (help)