Injection of Radioactivities into the Presolar Cloud: Convergence Testing

Abstract

According to the hypothesis of the triggered origin of the solar system, the formation of our planetary system was initiated by the impact of an interstellar shock wave on a molecular cloud core. The shock wave originated from a nearby explosive stellar event and carried with it radioactivities produced in the stellar source. In addition to triggering the collapse of the molecular cloud core, the shock wave also deposited some of the freshly synthesized radioactivities into the collapsing system. These radioactivities were then incorporated into the first solar system solids, in this manner leaving a record of the event in the meteoritic material. The viability of the scenario can be assessed by numerical simulations studying the processes involved in injecting shock wave material into the collapsing system. Calculations performed at different resolutions confirm the previously suggested conclusions: injection occurs through Rayleigh-Taylor instabilities, the injection efficiency is approximately 10%, and temporal and spatial heterogeneities in the abundances of the radioactivities in the early solar system are possible. The results are used to estimate dilution factors for different stellar sources.