Virial mass contours in a cooling diagram
= Virial mass contours in a cooling diagram
{title2=$n_H\propto T^3/M^2$}
Combining a virial-temperature relation with the density of a uniform self-gravitating sphere gives $M\propto T^{3/2}n_H^{-1/2}$. Thus contours of constant mass in a density-temperature plane satisfy $n_H\propto T^3/M^2$. Structural coefficients, composition and the distinction between baryonic and total gravitating mass matter when giving numerical labels.