Astronomers have used the James Webb Space Telescope to catch an extraordinary glimpse of a massive galaxy taking shape in the early universe. They identified a compact group of at least six galaxies that are likely to merge into a single enormous system. At the heart of this cosmic construction site…

The radio telescope LOFAR, with a major contribution from Leiden Observatory, has produced the most detailed radio map of the Universe ever made. Never before have so many cosmic radio sources been captured in a single survey: 13.7 million.

For the first time, astronomers have observed in three dimensions that gas from spiral galaxies is blown upwards and downwards at high speed, far out of the galaxy. They thereby confirm the theory of galaxy evolution: that star-forming galaxies create intergalactic gas flows by discharging gas along…

Leiden scientists lead COLIBRE, a groundbreaking set of cosmological simulations. By including key missing physics, cold gas and cosmic dust, they offer the most realistic picture yet of how galaxies formed and evolved since the dawn of time.

Two teams of astronomers, including one from Leiden University, have discovered oxygen in the most distant known galaxy, JADES-GS-z14-0. This groundbreaking discovery shows that galaxies could form much faster in the early universe than was previously thought.

Astronomers who simulate galaxies do not always get the same result, even when they start from identical conditions. New research from Leiden University shows that this is not a flaw, but a consequence of how galaxies behave — and how they are modelled.

Three Leiden researchers have been awarded a Vici grant by the Dutch Research Council. The funding of up to 1.5 million euros supports ‘talented, adventurous and pioneering researchers’. A total of 39 projects at Dutch institutions will receive a grant.

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.

Astronomers have discovered an enormous supply of cold molecular gas in a galaxy shortly after the Big Bang. The finding offers a rare glimpse of the raw material from which the first large galaxies were built. Measurements suggest that around 95 per cent of the normal matter in the galaxy studied,…

How do galaxies form? That is what astronomer Mariska Kriek will be researching in the coming years. She received an NWO Vici grant of 1.5 million euros to study galaxies in the early universe. ‘This research uses new and unprecedented observations from the James Webb Space Telescope (JWST). These allow…

Researchers have discovered the most distant Milky-Way-like galaxy yet observed. Dubbed REBELS-25, this disc galaxy seems as orderly as present-day galaxies, but we see it as it was when the Universe was only 700 million years old. This is surprising since, according to our current understanding of…

By looking at stars in dwarf galaxies research Bas Zoutendijk is trying to gain new insight into dark matter.

An international team of astronomers has discovered a large reservoir of hot gas in the cluster-in-formation around the Spiderweb Galaxy. Based partly on that hot gas, the astronomers predict that the cluster-in-formation will grow into one of the largest objects in the universe. A step closer to discovering…

The shock wave triggered by one of the five galaxies making up the iconic Stephan’s Quintet appears to be less disruptive than previously thought, with the shock likely being cushioned by dust particles in the surrounding gas. This is according to the analysis of the first scientific observations of…

Finally we know for sure that there is a black hole at the centre of our own galaxy. Today, astronomers unveiled the first ever photo of Sagittarius A*, a super-massive object at the centre of the Milky Way. This picture could only be taken thanks to the cooperation of telescopes worldwide.

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…

An international team of researchers led by astronomers from Leiden University (the Netherlands) has produced the first sharp radio maps of the universe at low frequencies. Thanks to a new calibration technique, they bypassed the disturbances of the Earth's ionosphere. They used the new method to study…

Simulations of galaxy formation provide much more information about galaxies than a telescope. Simulations have been improving significantly in recent years. Astronomer Evgenii Chaikin made such a significant contribution to this field that he graduated with honours on February 27th.

Astronomers have found complex organic ice outside the Milky Way for the first time. The discovery shows that the building blocks of life could arise early in the universe - and under a variety of conditions, said Leiden astronomer Will Rocha.

‘A Muslim and a Jew in the house of God.’ This is how historian Nadia Bouras introduced her recent conversation with colleague Sara Polak in Leiden’s Hooglandse Kerk. They discussed the rising tensions since the outbreak of the Israel-Hamas war. ‘Dare to ask each other questions.’

Simulation project EAGLE has won the 2022 Group Achievement Award of the Royal Astronomical Society. EAGLE is a large collection of simulations about the formation of galaxies. The largest simulation contains as many as 6.8 billion particles and took months to calculate on the world's fastest superc…

To understand the universe as a whole, simulations on a cosmic scale are required. An international team of astrophysicists, led by Leiden University, is today making one of the largest cosmological datasets ever available for free. It comprises more than 2.5 petabytes of simulation data.

Astronomer Joseph Callingham and his team have observed for the first time a clear signal from a giant burst from a star outside our solar system. This would have a devastating impact on any unfortunate planet orbiting the star.

Not everything that comes close to a black hole is swallowed by it. Black holes can also hurl material away, and that chance turns out to be considerably bigger than previously thought. Martijn Oei's accidental discovery and his subsequent research on it earned him a cum laude promotion on 12 Decemb…

PhD defence

PhD defence

PhD defence

Scientists from the consortium behind the Euclid space telescope, including researchers at Leiden University, have created the largest and most detailed visible-light image ever taken of the centre of the Milky Way. The image shows more than 60 million stars.

Astronomers in Leiden have used the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile to produce a new detailed image of the centre of our Milky Way. This allows them to investigate the life of stars in the most extreme region of our galaxy. The Leiden scientists, led by Katarzyna…

Galaxies in the early universe contain more dust and hidden star formation than previously thought. That's what Ivana van Leeuwen concludes in her PhD research, where she combines data from various telescopes to create a more complete picture.

PhD defence

Research

The supermassive black hole at the center of the Circinus galaxy is being fed with gas by two spiral arms. This is what PhD candidate Wout Goesaert discovered. But only a small percentage disappears into the black hole, the rest is ejected.

Henk Hoekstra and Alessandra Silvestri work on the astronomy and theoretical physics in the Euclid mission. These Dutch researchers are part of the mission.

Audio podcasts or audio recordings have a broad range of opportunities in education. Podcasts can be used to transfer knowledge (audio lectures), record interviews, record instructions for a field trip or to make a short radio documentary on location. Podcasts are a flexible medium, the small file size…

For over a year now, the James Webb Telescope has been sending stunning images that exceed astronomers’ expectations. The photos are fascinating to see, but what exactly are we looking at? Assistant professor Melissa McClure explains.