High redshift galaxy formation and reionization

Over the last decade observational cosmology has matured to the point where quantities such as the mass, composition, and age of the Universe are now measured with a precision of a few percent. In contrast, the formation of the highest redshift galaxies and their role in the reionization of the IGM remains very poorly understood. I will briefly review some constraints that may currently be placed on reionisation and high redshift galaxy formation from existing observations of high redshift galaxies and quasars. I will then describe the new era for the study of high redshift galaxies that will open following the construction of the next generation of low-frequency radio-telescopes, including LOFAR and the MWA. These telescopes will enable reionization to be studied directly, using tomography of the 21cm line to measure the distribution of neutral hydrogen. I will discuss how the power-spectrum of intensity fluctuations might probe aspects of early galaxy formation.