Physics Colloquium: Observing the First Stars with 21-cm Cosmology

Abstract:

Understanding the formation and evolution of the first stars and galaxies represents one of the most exciting frontiers in astronomy. Since the universe was filled with hydrogen atoms at early times, the most promising method for observing the epoch of the first stars is using the prominent 21-cm spectral line of hydrogen. This rich era of early cosmic history should include several events caused by stellar ultra-violet radiation and X-rays from early black holes. Work in this field is growing rapidly in anticipation of the first 21-cm observations. We have focused on predicting previously-unexpected signatures of cosmic populations and on developing methods for a model-independent analysis of upcoming data.