Various sets of 2D histograms binning the cells in our computational domain (panels a–e) at the epoch of protostellar birth. Panels a–d represent respectively radial velocity, density, entropy, and temperature as a function of radius. The solid (resp. dashed) black line in panel b displays the expected density profile for a free-falling gas (resp. for the collapse of an isothermal sphere). The solid (resp. dotted) black line in panel d represents the expected temperature profile for the collapse of an isothermal sphere with γ_eff = 1.1 (resp. γ_eff = 7/5). Panel e displays temperature as a function of density, where the overlaid solid black line displays a contraction with γ_eff = 1.1. Panel f represents the sum of the enclosed gas and radiative energies at radius r (solid line, see Eq. (15)), along with its constituent parts, namely internal (dashed line), kinetic (dotted line), and radiative energies (dash-dotted line).