Welcome to the website of Léon V.E. Koopmans, Professor of Astronomy at the Kapteyn Astronomical Institute of the University of Groningen.
My research focuses on understanding the formation of the first stars and galaxies, the nature of dark matter, and the structure and evolution of galaxies across cosmic time. I work at the interface of astrophysics, cosmology, instrumentation, and data analysis, with particular emphasis on 21-cm cosmology, low-frequency radio astronomy, and strong gravitational lensing.
A major part of my work is aimed at detecting the highly redshifted 21-cm signal from the Dark Ages, Cosmic Dawn, and Epoch of Reionization. This requires not only sensitive instruments but also a detailed understanding of calibration, beam effects, foreground emission, radio-frequency interference, and other instrumental and environmental systematics. I am involved in efforts that span theory, simulations, methodology, and observations, including work connected to LOFAR, NenuFAR, SKA-related science, and future space- and lunar-based low-frequency experiments.
A second major line of research uses strong gravitational lensing to study the mass distribution of galaxies, probe dark matter substructure, and investigate galaxy evolution. This work combines observations, modelling, and numerical methods to extract physical information from some of the most precise natural experiments available in astrophysics.
This website provides an overview of my research, publications, group members, and current activities.
Leon Koopmans' Research Group 