Star formation cosmic rate

Virtually all models for the ultimate energy source of GRBs involve an endpoint of stellar evolution, particularly of the most massive stars. Thus it has been proposed that the burst rate must be proportional to the overall cosmic star formation rate. This view is supported by the fact that the typical redshifts (z 1) associated with GRB host galaxies correspond to an epoch of early active star formation in the Universe. Burst counterparts also tend to be... 

---