Supernova-Triggered Molecular Cloud Core Collapse and the Rayleigh-Taylor Fingers that Polluted the Solar Nebula

TL;DR

This study uses advanced 3D hydrodynamics simulations to explore how supernova shock waves can trigger molecular cloud collapse and inject short-lived radioisotopes, explaining isotopic heterogeneity in the early solar system.

Contribution

First fully three-dimensional models of supernova-triggered collapse and isotope injection, revealing the formation of Rayleigh-Taylor fingers and their role in heterogeneity.

Findings

RT fingers in 3D models impact dense core regions

Injection efficiencies are consistent with observed isotope levels

Few RT fingers likely influence the solar nebula's heterogeneity

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 (AMR) 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 pc 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.