2014 Annual Science Report
Arizona State University Reporting | SEP 2013 – DEC 2014
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 protoplanetary 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 protoplanetary 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 protoplanetary 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 protoplanetary disks, pursuant to the second goal. We have especially concentrated on the role of external photoevaporation in affecting radial transport.
These themes have become the thesis topic of Astrobiology-supported graduate student Anusha Kalyaan, who is modeling volatile transport and snow lines in externally photoevaporated disks. She presented recent work at the Lunar and Planetary Science Conference in March 2014. Likewise, transport of volatiles through the outer portions of disks—-and the effect this has on Jupiter’s noble has abundances—-was explored by Astrobiology-supported student Nikhil Monga. These results were presented at two conferences in 2014, and led to publication of a paper in the Astrophysical Journal in late 2014 (published in Jan. 2015, technically).