  We have detected the H92alpha radio recombination line from two dwarf
starburst galaxies, NGC 5253 and He 2-10, using the Very Large Array. Both the
line data as well as the radio continuum data are used to model the properties
of the ionized gas in the centers of these galaxies. We consider a
multi-density model for radio recombination lines and show why previous models,
which were based on the assumption of gas at a single density, are valid in
many situations. The models show that the ionized gas has a density of ~10^4
/cc in both galaxies, with an effective size of 2-10 pc and a total mass of
about 10^4 Msun. The derived production rate of Lyman continuum photons is ~2.5
x 10^{52} /s in both the galaxies and the corresponding mass of stars (assuming
a Salpeter IMF) is ~10^5 msun. The implied stellar density shows that the
observed radio recombination lines arise from ionized gas around super star
clusters (SSCs) in both galaxies (these SSCs have been recently detected
through their radio continuum emission). The existence of ~10^4 Msun of ionized
gas within a few parsecs of an SSC places strict constraints on dynamical
models. Using simple arguments, the parameter space for a few possible models
are derived. The well known radio-FIR correlation also holds for NGC 5253,
although the radio emission from this galaxy is almost completely thermal. It
is shown that NGC 5253 is strong evidence that the component of FIR emission
from warm dust is correlated separately with the component of radio emission
from thermal bremsstrahlung.
