Explorations of the Epoch of Reionization

The Epoch of Reionization is the period when the first stars and galaxies formed and ionizing light escaped into the intergalactic medium, gradually ionizing and heating the entire Universe.

This period is of fundamental importance for understanding our Universe as the oldest stars, the first black holes and the `seeds´ of modern day galaxies formed during this era. However, this entire period remains poorly understood.

Basic facts such as when it started, when it ended and what were sources of ionizing photons, remain unknown.The key to a better exploration is the 21cm signal produced by neutral hydrogen in the intergalactic medium.

The Low Frequency Array (LOFAR) EoR collaboration of which I am a core member is attempting to detect this signal in a statistical sense.

The much more powerful Square Kilometre Array (SKA), soon to start construction, will revolutionize the field by producing actual images of the distribution of the signal.In this project we will interpret the next LOFAR-EoR data releases using the new inference framework we developed, thus putting tighter constraints on the state of in intergalactic medium during reionization.

We will also further develop this inference framework to be able to include other observational constraints and also to enable the use of the image data from SKA era. Lastly we will investigate the poorly understood final stages of reionization using world leading computer simulations.