Appendix C: Radio spectra

C.1. Radio spectra for the WN sample

Radio spectra of the WN sample using data from the literature. The two connected flux points indicate the spectral index used to select the source in the USS sample. Note the steeper spectra with higher frequency in most objects.

C.2. Radio spectra for the TN sample

Radio spectra of the TN sample using data from the literature. The two connected flux points indicate the spectral index used to select the source in the USS sample. Note the steeper spectra with higher frequency in most objects.

C.3. Radio spectra for the MP sample

Radio spectra of the MP sample using data from the literature and our ATCA observations (diamonds). The two connected flux points indicate the spectral index used to select the source in the USS sample. Note the steeper spectra with higher frequency in most objects.