Promotores: F.H. van Lunteren, F.P. Israel

In this thesis we push the boundaries of high-resolution imaging at radio frequencies between 100 and 200 MHz. Using the International LOFAR Telescope that spans across Europe we achieve sub-arcsecond angular resolution.

The thesis deals with the study of giant radio galaxies (GRGs), which are radio galaxies of megaparsec sizes.

This thesis focuses on the study of transient and variable radio sources in the universe.

The success of Dutch radio astronomy in the last century was largely due to Leiden astronomer Jan Hendrik Oort. He made astute use of circumstances in the post-war period. Historian Astrid Elbers' research focuses on this golden period.

This thesis explores the theoretical and observational properties of distant massive galaxies that harbour active black holes in their centres and shine brightly at radio wavelengths.

Within the field of astronomy, understanding how galaxies grow and evolve from the Big Bang to the present day is a challenging and complex question.

One of the key quests in astronomy is to study the growth and evolution of galaxies across cosmic time. Radio observations provide a powerful means of studying the formation of stars and subsequent buildup of distant galaxies, in a way that is unbiased by the presence of dust.

The LOFAR radio telescope produces petabytes of data every year. Radio Astronomers use complex multi-step pipelines to process this data and produce scientific images.

After almost twenty years the record for the most distant radio galaxy has been broken. A team of astronomers led by Leiden PhD candidate Aayush Saxena has discovered a radio galaxy from the time when the universe was just one billion years old. The galaxy is at a distance of 12 billion light years…

It has now been well established that shocks and turbulent motions in the intra-cluster medium (ICM) generated through cluster mergers can produce large-scale synchrotron emission.

No more lectures and exams for the Radio Astronomy course taught by Michiel Brentjens. The corona crisis is a moment of reflection that has changed his whole way of teaching. Instead of being in front of the class, he lets his students build a radio telescope with paint cans.

Promotor: H.J.A. Röttgering, Co-promotor: M. Haverkorn

An international team of scientists including Leiden's Joe Callingham has discovered nineteen red dwarf stars that unexpectedly emit radio waves. The outbursts possibly originate from interaction with exoplanets. The results of the research appear in two scientific publications.

A Dutch-Italian-German team of astronomers has observed a huge glow of radio emission around a cluster of thousands of galaxies. They combined data from thousands of LOFAR antennas that were focused for 18 nights on an area the size of four full moons. This is the first time astronomers have been able…

They are often referred to as ‘The Oscars of the Natural Sciences’: the Breakthrough Prizes in Life Sciences, Fundamental Physics and Mathematics. This year, the prize for physics went to the Event Horizon Telescope team, which took the first-ever picture of a black hole. Four Leiden astronomers were…

An international team of astronomers has published a map of the sky showing over 25,000 supermassive black holes. The map, to be published in the journal Astronomy & Astrophysics, is the most detailed celestial map in the field of so-called low radio frequencies. The astronomers, including Leiden astronomers,…

A galaxy is already incredibly large, but it can get even bigger. Astronomer Reinout van Weeren investigates clusters of galaxies, one of the largest structures in the universe. For his research into the origins and evolution of these clusters, he obtained an ERC Starting Grant of 1.5 million euros.…

An international team of astronomers led by Dutch scientist Martijn Oei has discovered the largest pair of jets from a black hole ever seen. The 'jumbojets' extend a combined length of 140 Milky Ways. The Leiden Observatory played a prominent role in this research. The publication will feature on the…

SRON Netherlands Institute for Space Research is moving. In 2021, the Utrecht branch will settle in South Holland. Assistant professor at TU Delft, Akira Endo leads a project that builds a state-of-the-art instrument for astronomical research. ‘SRON is the key to go from proof-of-concept to a science-grade…

The directorate of the Netherlands Research School for Astronomy (NOVA) has two new members. Ronald Stark (currently at NWO) will be the new Executive Director of NOVA from 1 September. Amina Helmi (Professor of Dynamics, structure and formation of the Milky Way at the University of Groningen) will…

Two Leiden astronomers will receive the prestigious IAU PhD Prize. Both Jorryt Mathee and Niels Ligterink of the Leiden Observatory won a prize. Scientific director Huub Röttgering: We are proud that this year two of our PhD students receive an IAU prize for the best thesis in their field of researc…