I am a staff astronomer at the observatory of Leiden University and work on the instrumentation projects ELT/METIS and VLTI/MATISSE.

My main research interest is in the nuclear regions of active galaxies (Active Galactic Nuclei, AGNs) which I study using very high spatial resolution techniques, such as infrared interferometry and adaptive optics, and with spectroscopy.

AGNs are thought to play a major role in transforming galaxies from gas-rich spiral galaxies to the so called ‘red and dead’ ellipticals, at least in the most luminous galaxies. There is some agreement that ‘AGN feedback’ is important in this transformation as it could push out the molecular gas out of which stars form. However, clear observational evidence for this outflow is very hard to collect, especially at high redshift where this ‘co-evolution’ mostly occurs. In ‘local’ AGNs, cosmic evolution does not play a role, but the physical processes in the nuclei can actually be resolved and studied in detail. It is my hope and my ambition that the insights we gain from resolved studies of the AGN phenomenon in the local universe will ultimately provide us with a better understanding of the global evolution of galaxies from the early universe until now.


May 2021 – New paper out on the nuclear stellar populations of a sample of ultra-hard X-ray selected AGNs and control galaxies (the LLAMA sample). See my Twitter summary here (please see the tweet on Twitter to view the entire thread of 17 tweets):

Upcoming events

This year’s annual conference of the European Astronomical Society, EAS 2021, will again be hosted by Leiden Observatory this year (like EAS 2020) and I am delighted to be part of the “hosting committee” again. Like last year, it will be a fully virtual conference. Besides conference organisation, I will be contributing to Symposium 10: The many faces of black hole accretion as organiser and with a poster.

EAS 2021 special session 30: Astronomy for planet EarthI am also the co-chair of Special Session 30: Astronomy for Planet Earth: forging a sustainable future. In this series of sessions (four 90 minute blocks) we will be discussing how to minimise astronomy’s carbon emissions today and for future facilities and how to best embed climate communication in our many outreach activities.

Click here to download a PDF version of the poster in full resolution.

My Tweets