The first stars and black holes

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400 million years after the Big Bang, the Universe appeared dark and empty as it slowly expanded. Suddenly the first stars formed, lighting up the Universe and forming the galaxies we see today. We have few observations of this era and it makes up over a billion year gap in our knowledge. Theories show that this is the era when stars were born with up to a hundred times the mass of our Sun, and the first black holes began to appear. These first objects gave out heat and light, making bubbles in the surrounding hydrogen gas that we will observe for the first time using radio telescopes. How these bubbles are shaped and how they grow will tell us how those first stars and black holes were born, lived and died. Searching for this signal is challenging since we don't know what it looks like and when we tune in to the radio waves, we also detect signals from everything from nearby exploding stars to mobile phones. This noise covers the first stars signal a 1000 times over, making the search for an unknown signal a true needle-in-a-haystack challenge. I have developed methods essential for removing that noise and finding that first star's signal, even despite not knowing what it looks like. Using my work to design the SKA, an array of millions of antennas in Australia, we will make observations stretching back into the Dark Ages of our Universe, creating a movie of our Universe growing up over a billion years. This project will involve working with real data from an SKA pathfinder called LOFAR. We will use techniques to remove the overwhelming amount of noise on top of this tiny signal, and extract everything we can about the astrophysics, using machine learning and Bayesian statistics. This project is suitable for someone who wants to get straight into the data, while using what we learn to inform the next generation facility, which is hot on our heels.