Evolving stellar models to find the origins of our galaxy

Abstract

After the Big Bang, it took about 200 million years before the very first stars would form - now more than 13 billion years ago. Unfortunately, we will not be able to observe these stars directly. Instead, we can observe the fossil records that these stars have left behind, preserved in the oldest stars of our own galaxy. When the first stars exploded as supernovae, their ashes were dispersed and the next generation of stars formed, incorporating some of the debris. We can now measure the chemical abundances in those old stars, which is similar to a genetic fingerprint that allows us to identify the parents. In this paper, we develop a Genetic Algorithm (GA) for identifying the parents of these old stars in our galaxy. The objective is to study the now extinct first stars in the universe - what their properties were, how they lived and died, how many they were, and even how different or alike they were. The GA is evaluated on its effectiveness in finding the right combination of ashes from theoretical models. The solutions found by the GA are compared to observational data. The aim is to find out which theoretical data, i.e., abundances of chemical elements, best matches the current observations.