1. The Quick and Dirty

Big Picture

The Bonnor Ebert density profile is coded into astrobear using an approximate analytic solution to the Lane-Emden equation. This function solves for the density contrast of the sphere from center to outer edge, as a function of the non-dimensional radius,#!latex \xi , where

xi ~=~ (\frac{4 \pi G \rho_c}{C_s^2})^\frac{1}{2}~r

Problem.data

The BE module requires the following 3 parameters to set up a BE sphere on the grid:

1. central density of the sphere (central_rho),
2. non-dimensional radius (xi),
3. dimensional radius (clump_rad).

These 3 parameters uniquely and completely specify a sphere in hydrostatic equilibrium as given by the Lane Emden equation (see). They are user-specified in problem.data.

Units