Why do black holes emit thermal radiation? And how does a closed quantum system thermalize?

The physical origin of the dozens of stellar-mass binaries, the mergers of which have been detected by the LIGO-Virgo-KAGRA collaboration via gravitational waves, is still unknown.

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.

Promotor: Prof.dr. E.F. van Dishoeck, Co-Promotor: M.R. Hogerheijde

What is dark matter? How do supermassive black holes form? ‘Primordial’ black holes might hold the answer to these long-standing questions. Leiden and Chinese cosmologists have identified a new way in which these hypothetical objects could be produced just after the Big Bang. Publication in Physical…

The Event Horizon Telescope (EHT) collaboration receives the 2021 Royal Astronomical Society Group Achievement Award. In April 2019, the EHT team presented the first-ever photograph of the shadow of a black hole. Leiden professor Huib-Jan van de Langevelde has been director of EHT since last year. Three…

Scientists are asking your help to find the origin of hundreds of thousands of galaxies that have been discovered by the largest radio telescope ever built: LOFAR. Where do these mysterious objects, which extend for thousands of light-years, come from? A new citizen science project called LOFAR Radio…

An international team of astronomers led by Matus Rybak (Leiden University) has proven, thanks to accidental double zoom, that millimetre radiation is generated close to the core of a supermassive black hole. Their findings have been accepted for publication in the journal Astronomy & Astrophysics.

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…

Meet the newest Full Professor at the Leiden Observatory: Joe Hennawi. All the way from Santa Barbara, California, Hennawi will strengthen the astronomy institute. In Leiden, he will use his recent ERC Advanced Grant to study how supermassive black holes come into existence.

This is the physics summer school of Leiden University. It is part of the Leiden Institute of Physics (LION). The summer school is intended for Bachelor (BSc) students in physics. It covers topics from quantum matter and optics, to biological & soft matter physics and cosmology and theoretical physics.…

Promotor: H.J.A. Rottgering, Co-Promotor: R.J. van Weeren

Physicists understand little about quantum matter, which is a building block of future quantum computers. Theorists have now discovered that black holes with ‘dreadlocks’ harbor a similarly exotic order pattern, which makes calculations on quantum matter easier. Publication in Physical Review Letter…

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,…

In this dissertation, matching, entropy, holes and expansions come together. The first chapter is an introduction to ergodic theory and dynamical systems.

Two black holes, in close orbit around each other. Have they slowly drifted together, or did they emerge from two orbiting stars? Together with to colleagues form Amsterdam, Leiden astronomer Simon Portegies Zwart calculated that the second scenario is rather likely.

The Dutch Black Holes Consortium receives 4.9 million euros from NWO for unravelling the mysteries of black holes and other mysteries of the universe. The Astronomy and Society group at Leiden Observatory is affiliated to use the leading research to introduce people of all ages and background, and children…

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.

Elena Maria Rossi is fascinated by black holes. Her appointment as a professor was a long-held wish, partly because there are so few female professors in her field. ‘My appointment is also a milestone for the Leiden Observatory.’

We don’t understand how some materials become superconducting at relatively high temperatures. Leiden physicists have now found a surprising connection with auxiliary black holes. It enables us to use our knowledge of black holes on the mystery of high-temperature superconductivity. Publication in Nature…

This thesis aims to enhance our understanding of galaxies by testing theoretical models of galaxy formation against observations, particularly in the cases of extreme systems which have been found to have an excess of baryonic mass in their central regions, in the form of either supermassive black holes…

An international team of astronomers has witnessed a cosmic weather event that has never been seen before.

Since the Middle Passage is in the North Atlantic, and the North Atlantic has a relationship with the arctic, what relationship does the Arctic have with the Middle Passage? How can this relationship be used to provide a space of healing by uncovering Afro/diasporic counter narratives?

At our Summer School on Philology and Manuscripts from the Muslim World we offer graduate students and researchers lectures by experts, practical classes, and hands-on experience with manuscripts from Leiden University’s famous collection of oriental manuscripts.

Discover the Summer Schools of Leiden University

Holidaymakers, day-trippers and tourists could book a university tour with a student as their guide in summer 2025.

‘Space Antenna LISA will open an unprecedented window on the Universe,’ says astronomer Elena Maria Rossi. The mission will be the first one to detect Gravitational Waves from space. These can tell us more about the beginning of our Universe and the formation of black holes. With an NWO grant of twelve…

For the first time, astronomers have managed to take a photo of a supermassive black hole and its shadow. They used the Event Horizon Telescope (EHT), a worldwide network of eight radio telescopes that together form a virtual telescope the size of the earth. The news was presented in six press conferences…

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…

We have conducted a full spectral line survey of the 3-13 micron region of two massive protostars, AFGL 2591 and AFGL 2136, for the first time at high spectral resolution.

Holidaymakers, day-trippers and tourists were able to book a University tour, with a student as their guide.

The annual Leiden Institute of Physics (LION) summer school offers outstanding bachelor students the opportunity to discover the research frontiers of modern physics. The programme includes seminars by renowned physicists on variety of topics, visits to research laboratories, and a range of social a…

An international team of astronomers led by Violeta Gámez Rosas (Leiden University) has observed a supermassive black hole hidden in a ring of dust. This discovery fits the idea that the so-called active centers of galaxies are much more similar than observations show, because the viewing angle from…

What physics controls the properties of quantum matter, such as how electrons flow inside high-temperature superconductors? This question has captivated the physics community and industry for decades, in part due to the great technological potential such materials have, but also because they have resisted…

Promotor: J. N. Kok, Co-promotor: A. J. Knobbe

The brightness peak of the ring around M87's supermassive black hole has shifted 30 degrees counterclockwise in a year. This is shown by new images released by the Event Horizon Telescope consortium.

Stars orbit black holes while jumping up and down. This is the prediction of a theoretical model developed by Leiden physicist Satish Kumar Saravanan, based on Einstein’s theory of relativity. He defends his PhD thesis on July 7th.

Are you a researcher eager to share your work with a broader audience? Do you want to develop your science communication skills and learn how to engage effectively with society? Then join our Summer School Science Communication in Leiden! Jointly organized annually by the Faculties of Science and Social…

One unravels the origin of the largest black holes in the universe, the other investigates the influence of stellar wind on the atmosphere of exoplanets. Both Elena Maria Rossi and Aline Vidotto receive a Vici grant for their research into the mysteries of the universe. ‘I have no idea yet how we can…

Promotor: M. Franx, Co-Promotor: I.F. Labbé

A European team of astronomers has discovered the largest stellar black hole in the Milky Way. It is more than thirty times as massive as our sun and is located in the constellation of Aquila, about two thousand light-years from Earth. The astronomers stumbled upon the black hole by chance while preparing…

Promotores: S.F. Portegies Zwart, E. M. Rossi

All supermassive black holes in the centres of galaxies appear to have periods when they swallow matter from their close surroundings. But that is about as far as the similarities go. That's the conclusion reached by British and Dutch astronomers from their research with ultra-sensitive radio telescopes…

Galaxies in the local Universe fall into two main categories of spirals and ellipticals. In this Thesis, we explore the structural evolution of galaxies into this bimodal distribution.

For only the second time ever, astronomers have linked a neutrino to an object outside our Milky Way. These observations were made using telescopes both on Earth and in space. The researchers, including Leiden astronomer Sjoert van Velzen, were able to trace the neutrino to a black hole that is devouring…