Inhomogeneities and the modeling of radio supernovae

Observations of radio supernovae often exhibit characteristics not readily accounted for by a homogeneous, spherically symmetric synchrotron model; e.g., flat-topped spectra/lightcurves. It is shown that many of these deviations from the standard model can be attributed to an inhomogeneous source structure. It is argued that the radio emission in Type Ib/c supernovae has a small volume filling factor and comes from a narrow region associated with the forward shock, while the radio emission region in SN 1993J (Type IIb) is determined by the extent of the Rayleigh-Taylor instability emanating from the contact discontinuity. Attention is also drawn to the similarities between radio supernovae and the structural properties of supernova remnants.