With the full-scale operations of the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope now underway, astronomy has entered a golden age of time-domain discovery. As we move away from finding just a few rare transients, the International Gemini Observatory serves as the essential bridge between discovery and characterization. This talk explores […]

In-person seminar Active Galactic Nuclei (AGN) play a central role in regulating galaxy evolution, yet the interplay between black hole accretion, star formation, and large-scale environment remains not well constrained. Using integral-field spectroscopy from the MaNGA survey, we find that nearby AGN host galaxies exhibit nuclear star formation rates 2–4 times higher than matched inactive […]

Modern sky surveys are now discovering comets at distances beyond 5 to 10 au from the Sun, a distance that is expected to increase with the upcoming Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST). However, the mechanisms driving comet activity at such distances remain poorly understood, as temperatures are too low […]

Abstract: The inference of the physical properties of galaxies at cosmological distance requires modeling a wide range of physics, including e.g. stellar evolution and atmospheres; dust attenuation and re-emission; nebular physics;  AGN emission; and more. Bayesian inference is often used to map the inevitable degeneracies, and the large amount of physics and wide parameter space […]

Abstract: Weak gravitational lensing is one of the most powerful probes of the large-scale structure of the Universe. Ongoing Stage-III surveys, including Subaru Hyper Suprime-Cam (HSC), Dark Energy Survey (DES), and Kilo-Degree Survey (KiDS), have already delivered competitive cosmological constraints using weak lensing measurements. To date, most analyses have relied primarily on two-point statistics, such […]

Galaxy mergers can strongly transform galaxies, but their impact depends critically on time since coalescence. Using UNIONS imaging and the MUMMI deep-learning framework, we identify large samples of galaxy mergers and assign post-merger timescales, allowing merger-driven evolution to be studied as a sequence rather than as a single population. With this framework, we track the […]

In-person seminar

In-person seminar

The hierarchical assembly history of our Milky Way galaxy has now been reconstructed in considerable detail, thanks to a combination of kinematic
and chemical evidence from Gaia and other surveys. As impressive as these results are, the Milky Way remains just one galaxy - how can we generalise
these results to other galaxies? How typical is the Milky Way? Even in the era of 30-40 m class telescopes, detailed studies of individual stars in galaxies beyond the Local Group will remain challenging, but I will argue that stellar clusters can play an important role as tracers of the early assembly histories of external galaxies. Interesting results have already emerged over the past decade from studies of Local Group GCs, including evidence of accretion in the M33 GC system and the discovery of the extremely metal-poor cluster EXT8 in M31. Future spectroscopic surveys with instruments such as the MOSAIC spectrograph on the ELT, following up on imaging by Euclid, Roman, and others, promise to enable such work on a much grander scale.

The colour–magnitude diagrams (CMDs) of star clusters underpin stellar astrophysics. They calibrate stellar evolution models, enable age-dating of stellar populations, and provide templates for interpreting unresolved galaxies. Yet the CMDs of young massive clusters show surprising features, such as split main sequences and extended turn-offs. This raises the question of whether we truly understand the mechanisms governing stellar distributions across the CMD.
In this talk, I will show how binary interactions and stellar rotation reshape CMD morphologies. Using observations of young massive clusters in the Magellanic Clouds obtained with HST and MUSE, we measure the spin velocities of large stellar samples and characterise the clusters’ binary populations. Our results reveal distinct populations of slow and fast rotators occupying different loci in the CMD. The detection of post-interaction binaries, such as blue stragglers and stripped stars, further enables us to constrain population synthesis models and to assess the contribution of massive star clusters to the cosmic rate of compact binary mergers observed via gravitational waves.