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Constraining Galactic Transport and Distribution of Radionuclides

Supervisors: Dr. Brandt Gaches & Prof. Stefanie Walch-Gassner

Radionuclides are short lived radioactive isotopes which existed in the beginning of the solar system and have since decayed below measureable amounts. These radionuclides can be diagnostics of the environment of the early solar system. Some radionuclides, such as 26Al and60Fe, are formed during the end stages of star formation, such as high-mass star winds and Type II supernova (e.g. Cameron & Truran, 1977; Gaidos et al., 2009; Tachibana et al., 2006; Boss, 2019; Kuffmeier et al., 2016). Others, such as 10Be, signify enhanced particle irradiation of the early solar system (Lee et al., 1998; Gounelle et al., 2007). 26Al is of particular importance: 26Al within planetesimals can provide enough heat through radioactive decay to produce differentiated (and potentially molten) planetesimal cores (Wadhwa et al., 2007; Dauphas & Chaussidon, 2011). Since the discovery of 26Al by Lee et al. (1976), there have been several proposed mechanisms to enrich the solar system, with the external mechanisms mentioned above being the most promising. However, previous numerical studies of galactic isotope enrichment have used either simple geometries or have had to sacrifice numerical resolution. The SILCC simulations, along with SILCC-Zoom, provide an ideal laboratory for testing the injection and transport of isotopes in galaxies from supernova and high-mass stellar winds. During the project, the Master’s student will gain expertise in numerical development and simulations, atomic isotope physics, and data analysis of the resulting simulations. Furthermore, the project provides an ideal setting for interdisciplinary work, with the potential to work with geochemists at UoC and in the United States through the Univeristy of Texas Center for Planetary Systems habitability. The project will be composed of two steps:

  • Implementing both tracer particles and scalar fields into the Flash 4.3 magneto- hydrodynamic code with the SILCC collaboration at UoC. The implementation will use state-of-the-art stellar wind and supernova models to calculate the injection of a wide range of radioactive isotopes, in particular 26Al, 41Ca and 60Fe. The simulations will be post-processed to analyse the distribution of important radioactive isotopes in the galactic disk. Further analysis can be done to calculate correction functions on the abundance of isotopes with respect to nearby star-forming regions.

  • Meteorites and chondrules provide a crucial history of the radionuclide contamination within our solar system. Working with existing geochemistry results for isotopes to put constraints on possible environments the Solar System may have formed.