We propose a comprehensive analysis of the injection of supernova material into forming planetary systems, both in the pre-collapse molecular cloud stage as well as the protoplanetary disk stage. Our scientific objectives are the following: Build predictive models of the elemental variations in forming stars caused by supernova contamination, and assess how much of the observed variations can be attributed to supernova injection. Predict the efficiency by which short-lived radionuclides such as 26Al and 60Fe can be injected into forming planetary systems by nearby supernovae. Assess whether potentially observable proxy elements (such as P) created in the same zones in supernovae as key short-lived radionuclides (such as 26Al) follow the same histories after the supernova as both are injected into forming planetary systems. Assess the origin of presolar grains in our own Solar System, and test the hypothesis that a subset of them (low-density graphite) arose from the same supernova that gave rise to the short-lived radionuclides in the early Solar System. Elemental ratios such as C/O and C/Si have obvious effects on the chemistry in a forming planetary system, and the bulk composition of its planets (Kuchner&Seager 2005). Short-lived radionuclides in a planetary system may play a dominant role in determining delivery of bioessential volatiles (including water) to terrestrial planets (Desch & Leshin 2004; Morris & Desch 2009, submitted to Astrobiology). The presolar grain record can yield details about the Solar Systems formation if the grains themselves can be placed in the proper context. The theoretical studies we propose here will also influence targeting priorities of NASA missions such as New Worlds Observer. To achieve our scientific objectives, we will use the mature code FLASH to conduct 2D and 3D simulations of the interaction of supernova ejecta with planetary systems in the two most common stages of formation that are observed in proximity to massive stars on the verge of exploding as supernovae. These include protoplanetary disks such as those observed in H II regions, and molecular gas immediately behind ionization fronts in those regoins, which is often observed to be forming stars. The structure of the ejecta will also be varied, from isotropic ejecta to very clumpy ejecta consistent with the X ray imaging of ejecta in the Cas A supernova remnant (Hwang et al. 2004). For each scenario we will investigate the hydrodynamics of the gas and the efficiency of injection of supernova material in the gas phase. We will also post-process the hydroydnamic data, developing a computational tool to calculate the dynamics and thermal evolution of dust grains entrained in the ejecta as they interact with the cloud cores or disks. We will ascertain whether dust grains of different sizes and compositions can be efficiently injected without being destroyed. Besides publishing a number of papers in scientific journals, we expect our research to have a broader impact. For the scientific community, we will make freely available our computational tool that calculates the dynamical and thermal history of dust grains in astrophysical flows. The computational techniques as well as scientific results arising fromthis research will be incorporated into the undergraduate curriculum within the School of Earth and Space Exploration. We are committed also to communicating the results of our research to the public through a variety of channels that already exist at Arizona State Univerity (ASU). In this document we provide background describing the importance of determining the extent of injection of supernova ejecta into forming planetary systems. We then outline our proposed research, the numerical techniques to be employed, and our expected results. Finally we described the broader impacts of our research.
|Effective start/end date||7/1/09 → 6/30/13|
- National Science Foundation (NSF): $497,299.00