In: Physics
Let’s look at some gravitational potentials and the density profiles that can generate them.
i) For ρ(r) = ρ◦r ◦^2/r^2 , what is the corresponding gravitational potential?
ii) For Φ(r) = −GM/[b + √ (b ^2 + r ^2)], what is the corresponding density profile?
iii) For Φ(R, z) = Φ◦ln[ (R ◦^2+R ^2+(z ^2/q^2))/R◦^2 ], what is the corresponding density profile ρ(R, z)? In this expression, the constant q controls the axis ratio of the potential, where q = 1 would be spherically symmetric and q < 1 means that the potential is “flattened” a bit along the z-axis. Does something strange happen along the z axis if q < 0.7 ?