My research

I am a theoretical astrophysicist and my research focuses on understanding how the earliest galaxies formed in the "dark ages", how they changed the infant Universe, and how they have evolved into the structures we see around us today. I'm also very interested in interdisciplinary topics such as Astrobiology.

The Epoch of reionization

The earliest galaxies produced light to (ionize) break up all of the hydrogen in the Universe into electrons and protons, starting the "Epoch of reionization". My work focuses on building models to understand the history of this process, that marks the last major phase change in the Universe.

Nature of early galaxies & where are they today?

Instruments such as the Hubble Space Telescope are proving the first glimpses of the galaxies forming in the very heart of the dark ages. My work focuses on understanding the physical properties of these galaxies and how they evolved through cosmic time into the structures we see around us today.

The nature of Dark Matter - warm or cold?

The earliest galaxies are the key sources of reionization photons, and the first and smallest building blocks of all the structures we see around us. We can therefore use them as excellent testbeds of models where Dark Matter is made up of  fast moving Warm particles, as compared to the standard "Cold Dark Matter" paradigm.

Metallicity relations in the local Universe

More than 150,000 galaxies in the local Universe show a very tight correlation between the total stellar mass, star formation rate and gas-phase metal mass - the "Fundamental Metallicity relation" (FMR). One of the topics of my research is to understand the physics, and time-evolution of this relation.