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Description
We explore the sensitivity of nucleosynthesis in massive stars to the truncation of supernova explosions above a certain mass. It is assumed that stars of all masses contribute to nucleosynthesis by their pre-explosive winds, but above a certain limiting main sequence mass, M_BH_, the presupernova star becomes a black hole and ejects nothing more. The solar abundances from oxygen to atomic mass 90 are fit quite well assuming no cutoff at all, i.e., by assuming all stars up to 120M_{sun}_ make successful supernovae. Little degradation in the fit occurs if M_BH_ is reduced to 25M_{sun}_. If this limit is reduced further however, the nucleosynthesis of the s-process declines precipitously and the production of species made in the winds, e.g., carbon, becomes unacceptably large compared with elements made in the explosion, e.g., silicon and oxygen. By varying uncertain physics, especially the mass loss rate for massive stars and the rate for the ^22^Ne({alpha},n)^25^Mg reaction rate, acceptable nucleosynthesis might still be achieved with a cutoff as low as 18M_{sun}_. This would require, however, a supernova frequency three times greater than the fiducial value obtained when all stars explode in order to produce the required ^16^O. The effects of varying M_BH_ on the nucleosynthesis of ^60^Fe and ^26^Al, the production of helium as measured by {Delta}Y/{Delta}Z, and the average masses of compact remnants are also examined.
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