Nucleosynthesis in Supernova Models. II. The ¹²C Detonation Model

The predictions of nucleosynthesis resulting from Arnett's 13C-detonation model of supernovae are examined quantitatively. For the first time the change in composition is integrated explicitly through expansion and "freeze-out" for a plausible model of stellar explosion. The predicted abundances are in excellent agreement with the iron-group abundances observed in the solar system (provided the "meteoritic" value for iron is used). An important, hitherto unknown nucleosynthesis effect is discovered which promises to explain the high-Z side of the iron abundance peak. However, even though the iron-group abundances are well reproduced, this model fails to produce sufficient quantities of intermediate-Z material, that is, species with 6 < Z < 21. Thus the model appears to be inconsistent with a combination of standard models of galactic evolution and the observed constancy of metal abundances relative to iron in stars of varying metal content. To avoid this inconsistency a supernova model should produce nearly att the elements between 6 < Z < 28 (at least) in the proper ratios. The implications of these calculations for other supernova models, for galactic evolution, and for nucleosynthesis theory are discussed in detail.