# Conversion between density and column density

by bagherihan
Tags: column, conversion, density
 P: 7 What's the way to convert n(r) to $\rho(r)$ in case of a spherical cloud. n(r) is the column density, $\rho(r)$ is the density. I tried (but didn't manage) to get it from their relation to the total mass: $M = 4 \pi \int r^2 \rho(r)dr = 2 \pi \int r n(r)dr$ (is it correct anyway?) Thank you,