Triggering Collapse of the Presolar Dense Cloud Core and Injecting Short-lived Radioisotopes with a Shock Wave. VI. Protostar and Protoplanetary Disk Formation

Abstract

Cosmochemical evaluations of the initial meteoritical abundance of the short-lived radioisotope (SLRI) 26 Al have remained fairly constant since 1976, while estimates for the initial abundance of the SLRI 60 Fe have varied widely recently. At the high end of this range, 60 Fe initial abundances have seemed to require 60 Fe nucleosynthesis in a core-collapse supernova, followed by incorporation into primitive meteoritical components within ∼1 Myr. This paper continues the detailed exploration of this classical scenario, using models of the self-gravitational collapse of molecular cloud cores that have been struck by suitable shock fronts, leading to the injection of shock front gas into the collapsing cloud through Rayleigh–Taylor fingers formed at the shock–cloud interface. As before, these models are calculated using the FLASH three-dimensional, adaptive mesh refinement, gravitational hydrodynamical code. While the previous models used FLASH 2.5, the new models employ FLASH 4.3, which allows sink particles to be introduced to represent the newly formed protostellar object. Sink particles permit the models to be pushed forward farther in time to the phase where a ∼1 M ⊙ protostar has formed, orbited by a rotating protoplanetary disk. These models are thus able to define what type of target cloud core is necessary for the supernova triggering scenario to produce a plausible scheme for the injection of SLRIs into the presolar cloud core: a ∼3 M ⊙ cloud core rotating at a rate of ∼3 × 10 −14 rad s −1 or higher.