The First Billion Years: From the First Stars to the First Galaxies

The first stars in the universe are thought to be massive, forming in dark matter halos with masses around 10$^6$ solar masses. Recent simulations suggest that these metal-free (Population III) stars may form in binary or multiple systems. Because of their high stellar masses and small host halos, their feedback ionizes the surrounding 3 kpc and drives the majority of the gas from the potential well. The next generation of stars then must form in this gas-poor environment, creating the first galaxies that produce the majority of ionizing radiation during cosmic reionization. I will review the latest developments in the field of Population III star formation and feedback and its impact on galaxy formation prior to reionization. In particular, I will focus on the numerical simulations that have demonstrated this sequence of events, ultimately leading to cosmic reionization, and their connections with nearby dwarf galaxies.