EVOLUTION OF SUPERNOVA EXPLOSION RATES IN THE UNIVERSE

The prospects of detecting extragalactic supernovae (SNs) down to visu al magnitudes 23-25 give us hope for observing them in the most distan t parts of the universe. Using a Monte Carlo method of stellar populat ion synthesis (the Scenario Machine), we compute, under standard assum ptions of stellar evolution, the rates of SNs of various types in a mo del galaxy and evaluate the SN rates in the universe. The expected cum ulative distribution log N - m (number of events - stellar magnitude) is calculated for various SN types and different star formation histor ies in the universe. The results are also presented in terms of evolut ion of supernova units with redshifts. Recent observational data on th e high-redshift SN Ia rate are in good agreement with our predictions for the relative density of baryons contained in stars at the present time (Omega = 0.0057).