Supernova-triggered molecular cloud core collapse and the rayleigh-taylor fingers that polluted the solar nebula

Abstract

A supernova is a likely source of short-lived radioisotopes (SLRIs) that were present during the formation of the earliest solar system solids. A suitably thin and dense supernova shock wave may be capable of triggering the self-gravitational collapse of a molecular cloud core while simultaneously injecting SLRIs. Axisymmetric hydrodynamics models have shown that this injection occurs through a number of Rayleigh-Taylor (RT) rings. Here we use the FLASH adaptive mesh refinement hydrodynamics code to calculate the first fully three-dimensional (3D) models of the triggering and injection process. The axisymmetric RT rings become RT fingers in 3D. While ∼100 RT fingers appear early in the 3D models, only a few RT fingers are likely to impact the densest portion of the collapsing cloud core. These few RT fingers must then be the source of any SLRI spatial heterogeneity in the solar nebula inferred from isotopic analyses of chondritic meteorites. The models show that SLRI injection efficiencies from a supernova several parsecs away fall at the lower end of the range estimated for matching SLRI abundances, perhaps putting them more into agreement with recent reassessments of the level of 60Fe present in the solar nebula. © © 2012. The American Astronomical Society. All rights reserved.