2013 Annual Science Report
Arizona State University Reporting | SEP 2012 – AUG 2013
Astrophysical Controls on the Elements of Life, Task 4: Model the Injection of Supernova Material Into Protoplanetary Disks
The goal of this project has been to determine whether supernova material could be injected into a proto-planetary disk, the disk of gas and dust from which planets form. A secondary issue is whether these materials would be mixed within the disk efficiently, and whether such an injection into our own proto-planetary disk can explain the isotopic evidence from meteorites that the solar system contained short-lived radionuclides like 26Al.
The first goal of this project was achieved in previous years. This line of inquiry was not as actively pursued, as it was discovered in previous years that the probability of injection into a proto-planetary disk is roughly 10-3 which, while not implausible, is much lower than the probability of injection into a molecular cloud, roughly 10-1. Modeling efforts have been concentrated into Task 4, understanding how supernova material can be injected into molecular clouds.
Nevertheless, we have continued to investigate how material is mixed and transported in proto-planetary disks, pursuant to the second goal. The role of external photo-evaporation in affecting radial transport, identified by Desch (2007) and Desch (2012, LPSC abstract), has been investigated in particular. It has become the thesis topic of Astrobiology-supported graduate student Anusha Kalyaan, who is modeling volatile transport and snow lines in externally photo-evaporated disks.