Citation for the 2017 RAS 'A' Fowler Award    Dr Jonathan Pritchard

 

The Fowler Award for Astronomy is awarded to Dr Jonathan Pritchard.

 

Dr. Jonathan Pritchard is a highly original theorist working in the area of 21-cm cosmology and the epoch of reionisation. His work has shownhow redshifted 21-cm radiation in absorption and emission can be used to map neutral hydrogen gas in the Universe, and thereby disentangle the history of galaxy formation and understand the first sources of ionising radiation. In a key contribution, he developed a comprehensive understanding of the three-dimensional 21-cm signal for all relevant redshifts (both before and after reionisation) and spatial scales, highlighting the different contributions of fundamental physics and astrophysics. Prior to this work, the theoretical understanding of the 21-cm signal was fragmented into differentregimes of physical interest. His pioneering work had a critical influence on the design of 21-cm observatories, and he is now contributing to making these observations a reality through his leadership in a series of international experiments. His contributions have been both broad and deep, ranging from analytic calculations and numerical modelling to data analysis. Dr. Pritchard has also published influential work on extracting fundamental physics from cosmic microwave background measurements and galaxy surveys.

 

For these reasons, Dr Pritchard is awarded the Fowler Award.