Research

How does the Universe form and evolve?
How do galaxies and black holes assemble?
What is our own place within the Universe?

These are some of the key questions I am addressing at the University of Cambridge. Galaxies provide a unique laboratory to unravel a wide range of physical processes that range from small to large scales, from star formation and stellar evolution to cosmological gas accretion and the large-scale cosmic web. The past two decades have been momentous in understanding the build-up of galaxies through most of cosmic time, especially in terms of their global properties and behavior. Today, the unknown physics of star formation and feedback represent the main uncertainty in our understanding of galaxy formation. We adopt a multifaceted approach between theory and observations in order to shed new light onto the physics of galaxies, black holes and dark matter. Our long-term goal is to spatially and temporally resolve galaxies in the young universe both with observations and theory in order to revolutionize the field and lead to the much needed insight into the physics of star formation and feedback. Our research group is centered on understanding the physics that drives the internal workings of galaxies using strategies that connect the spatially resolved scales within galaxies to their global properties and cosmological environments through cosmic time.

Studying galaxies with the most powerful telescopes

The research in our group is driving by observational discoveries. New ground-based instrumentation with adaptive optics (AO) capabilities in conjuncture with Hubble Space Telescope (HST) has shifted the focus of studies of distant galaxies: from measuring integrated properties to detailed measurements on spatially resolved scales. We conducted several investigations based on the largest and deepest AO-assisted near-infrared integral field unit (IFU) spectroscopic program at the Very Large Telescope (VLT), which led to several breakthroughs that shaped our current understanding of galaxy evolution at cosmic noon. Specifically, our observational work – published in Science – led to the discovery that the most massive systems at cosmic noon (3 billion years after the Big Bang) sustain their high star-formation rates at large radii in rotating disk components, while hosting fully-grown and already quiescent bulges in their cores. Now, the James Webb Space Telescope (JWST) is offering unprecedented sensitivity at infrared wavelengths for exploring reionization-epoch galaxies on spatially resolved scales. Read more about this below.

Models to pin down the physics of galaxies

We lead the development and analysis of numerical and analytical models to interpret our observations and to draw inspiration for new observational projects. Using cosmological simulations (see movie on the right from the IllustrisTNG collaboration), we found that the simulated galaxies oscillate about the star-formation equilibrium state, where the spatial distribution of star formation and the build-up of bulges are linked to these galactic-scale oscillations. Additionally, we developed an analytical model for the evolution of reionization-era galaxies, which we used to study which galaxies are driving reionization. Furthermore, we pioneered a new framework to quantify the variability of star-formation histories by means of the temporal power spectrum density. Read more about on-going projects below.