Misplaced Pages

Singular isothermal sphere profile

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

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.).

Density distribution

ρ ( r ) = σ V 2 2 π G r 2 {\displaystyle \rho (r)={\frac {\sigma _{V}^{2}}{2\pi Gr^{2}}}}

where σV 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 total mass calculated by integrating the function out to infinite radius does not converge (i.e., is infinite). However, it is commonly utilized in the literature due to the simplicity of its form.

See also

References

  1. Keeton, C. (June 2002). "A Catalog of Mass Models for Gravitational Lensing". arXiv:astro-ph/0102341v2.
Categories: