THE METALLICITY DEPENDENCE OF THE MINIMUM MASS FOR CORE-COLLAPSE SUPERNOVAE

Understanding the progenitors of core-collapse supernovae (SNe) and their population statistics is a key ingredient for many current studies in astronomy, but as yet this remains elusive. Using the MESA stellar evolution code, we study the dependence of the lower mass limit for making core-collapse SNe a function of initial stellar metallicity. We find that this mass limit is smallest at [Z] approximate to -2 with a value of similar to 8.3 M-circle dot. At [Z] = 0 the limit is similar to 9.5 M-circle dot and continues to rise with higher metallicity. As a consequence, for a fixed initial mass function the SN rate may be 20%-25% higher at [Z] = -2 than at [Z] = 0. This affects the association of observed SN rates as a probe for the cosmological star formation rate, rate predictions for SN surveys, and population synthesis studies.