  The reionization of the intergalactic medium (IGM) was likely inhomogeneous
and extended. By heating the IGM and photo-evaporating gas from the outskirts
of galaxies, this process can have a dramatic impact on the growth of
structures. Using a suite of spherically-symmetric collapse simulations
spanning a large parameter space, we study the impact of an ionizing
ultraviolet background (UVB) on the condensation of baryons onto dark matter
halos. We present an expression for the halo baryon fraction, which is an
explicit function of: (i) halo mass; (ii) UVB intensity; (iii) redshift; (iv)
redshift at which the halo was exposed to a UVB. We also present a
corresponding expression for the characteristic or critical mass, defined as
the halo mass which retains half of its baryons compared to the global value.
Since our results are general and physically-motivated, they can be broadly
applied to inhomogeneous reionization models.
