The energetic constraints on mechanisms for producing the spectral distortion of the microwave background claimed by Matsumoto et al., (1988) are investigated in the light of the new upper bounds on the cosmological baryon density derived by Kawano et al., (1988) from primordial nucleosynthesis. The thermal emission from dust heated by stars at large redshift and Compton scattering by a hot intergalactic medium heated by supernova explosions are considered, and it is concluded that both mechanisms fail on energetic grounds if they rely on stars formed with the same mass function as is observed in the solar neighborhood.
Lacey, C. G., & Field, G. B. (1988). Energetic constraints on spectral distortions of the microwave background. Astrophysical Journal, 330(7), L1-L4. https://doi.org/10.1086/185191