Example of an equilibrium ionization profile inside and around a spherically symmetric object: the fractions x_e = n_e/(n_e + n_H) and x_H = n_H/(n_e + n_H) are shown as a function of radius. We assume that the object has a baryonic mass of 10⁶ M_☉ and a density profile ∝1/r², with a factor of 50 drop in the density at the edge of the object (r ~ 150 pc), outside of which the density is uniform and equal to the background value at z = 50. A fraction f_star = 4% of the baryons in the object are converted into stars with the emission spectrum shown in Fig. 3. The vertical dashed line shows the radius of the Strömgren sphere when recombinations in the object are ignored; this can be used to infer the escape fraction of ionizing photons of 3.3%.