Supernova mixing to reproduce isotopic ratios of presolar grains

Presolar grains are considered to have traces in their birth before the solar system formation in their isotopic and elemental features. Most of silicon carbide type X (SiC X) and low density graphite grains show the excesses of 12C and 28Si. These isotopic features suggest that SiC X and low density graphite are originating from supernovae. On the other hand, elemental signatures of the grains suggest the grain formation in carbon-enriched materials, although the bulk composition of supernova ejecta is oxygen-rich. Therefore, the parent materials of the grains should have been formed by large-scale inhomogeneous mixing during supernova explosions to reproduce isotopic elemental signatures of presolar grains from supernovae. We investigate supernova mixtures reproducing isotopic ratios of individual single SiC X and low density graphite grains. We consider seven-layer mixtures of supernova ejecta. We seek mixtures reproducing as many isotopic ratios as possible of each of the grains. Then, the mixtures reproducing five and six isotopic ratios of SiC X grains and low density graphite grains are obtained, respectively. The mixtures are classified into three groups based on reproduced isotopic ratios. The main component of the mixtures is one of deep Ni-rich layer, outer He/C layer, and He/N layer. The C/O ratios of most of the mixtures are larger than 1. The ratios of Fe/C and Fe/Si are different between the mixtures corresponding to SiC X and low density graphite grains.