The influence of macroclumps for free-free spectral energy distributions
(SEDs) of ionized winds is considered. The goal is to emphasize distinctions
between microclumping and macroclumping effects. Microclumping can alter SED
slopes and flux levels if the volume filling factor of the clumps varies with
radius; however, the modifications are independent of the clump geometry. To
what extent does macroclumping alter SED slopes and flux levels? In addressing
the question, two specific types of macroclump geometries are explored: shell
fragments ("pancake"-shaped) and spherical clumps. Analytic and semi-analytic
results are derived in the limiting case that clumps never obscure one another.
Numerical calculations based on a porosity formalism is used when clumps do
overlap. Under the assumptions of a constant expansion, isothermal, and fixed
ionization wind, the fragment model leads to results that are essentially
identical to the microclumping result. Mass-loss rate determinations are not
affected by porosity effects for shell fragments. By contrast, spherical clumps
can lead to a reduction in long-wavelength fluxes, but the reductions are only
significant for extreme volume filling factors.Comment: to appear in MNRA
