Editing Stellar dynamics (section)

=== Density of a thick disk from Poisson Equation ===

Insert in the cylindrical Poisson eq. 
<math display="block"> \rho(R,z) ={\partial_z \partial_z \Phi \over 4 \pi G} + {\partial_R (R\partial_R \Phi) \over 4 \pi G R} = { M_0 R_0/z_0 \over 4\pi (R^2+R_0^2)^{3/2}} H(z_0-|z|), </math>
which drops with radius, and is zero beyond <math> |z| > z_0</math> and uniform along the z-direction within the boundary.

[[File:Density of a thick disk model.pdf|thumb|Note the vertically uniform thick disk density contour in this R0=5z0=1 model]]