Jacob Teffs

Date of Award

January 2018

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics & Astrophysics

First Advisor

Tim Young

Abstract

Population III stars are the first stars formed after the Big Bang, comprised of primarily

hydrogen and helium and lack heavy elements from previous generations. Using the

one-dimensional radiation-hydrodynamics code BOOM, a grid of eighteen stellar models

with masses of 15-80 solar masses , are exploded under a low and high explosion energy criteria.

Three types of central compact remnants are considered. The 3208 isotope TORCH nuclear

reaction network is used to calculate the nucleosynthesis that occurs during the

supernovae. The two convection criteria, Ledoux and Scharzschild, produce vastly

different stellar structures and thus produce different nucleosynthetic trends. When

comparing the numerically calculated abundances to observed extremely metal poor stars

([Fe/H] < −3), it is found that even using abundances from both the Schwarzschild and

Ledoux convection model a fit was not possible. The overall Ni-56 production claculated

for a given distribution and the peak production of Ni-56 is compared to observationally

calculated values from Population II supernovae. We show that for high energy

Schwarzschild models, integrated over a Salpeter initial mass function, the yields

approach that of the more compact lower energy Ledoux series, but heavier elemental

abundances of these metal poor stars need to be observed and determined to better fit the

data. The produced nickel for both series is high compared to observational work and is

likely to be lessened for larger central remnants.

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