1998ApJ...506L..85C

The decimetric luminosity of many galaxies appears to be dominated by synchrotron emission excited by supernova explosions. Simple models suggest that the luminosity is directly proportional to the rate of the supernova explosions of massive stars averaged over the past ~3x10⁷ yr. The proportionality may be used, together with models of the evolving 1.4 GHz luminosity function, to estimate the global star formation rate density in the era z≲1. The local value is estimated to be 0.026 M_☉.yr^–1.Mpc^–3, twice the value inferred from the Hα luminosity density. The value at z~1 is found to be 0.30 M_☉.yr^–1.Mpc^–3. The tenfold increase in the star formation rate density is consistent with the increase inferred from millimeter-wave, far-infrared, ultraviolet, and Hα observations.