Plummer model
= Plummer model
{c}
{title2=$\psi=GM/\sqrt{a^2+r^2}$}
The spherical <Plummer model> has $\psi=GM/\sqrt{a^2+r^2}$ and $\rho=3Ma^2/[4\pi(a^2+r^2)^{5/2}]$. It is the $p=2$ <hypervirial model>. In unit scales its isotropic distribution is $24\sqrt2E^{7/2}/(7\pi^3)$ for positive <relative energy>.