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,…

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.

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…

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?

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

The Sun and all the stars in the night sky reside in the Milky Way galaxy. In the at-rest reference frame of the Galaxy, typical stars travel with velocities of about 100-200 kilometres per second.

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

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

An Active Galactic Nucleus (AGN) is a highly luminous region at the center of a galaxy, powered by the accretion into a supermassive black hole and emitting energy from radio waves to gamma rays, often outshining the host galaxy.

In this thesis, we use low-frequency and high-frequency radio observations to address the following questions regarding quasars: is the radio loud/quiet quasar dichotomy real?

In this book Adam Fairclough chronicles the odyssey of black teachers in the South from emancipation in 1865 to integration one hundred years later.

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…

Optimization tasks in practice have multifaceted challenges as they are often black box, subject to multiple equality and inequality constraints and expensive to evaluate.

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.

Lecture, Studium Generale

In White Lies and Black Markets, Fatah-Black offers a new account of the colonization of Suriname—one of the major European plantation colonies on the Guiana Coast—in the period between 1650-1800.

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

Through the clever use of two types of telescopes, a team of researchers has produced stunning images of clusters of galaxies. This not only produces beautiful images, but also provides more information about the enormous amounts of energy released around supermassive black holes in clusters. The astronomers,…

Continuous optimization is never easy: the exact solution is always a luxury demand and the theory of it is not always analytical and elegant.

This book is the first systematic analysis of the changes in the use of goods and services by households of Black South Africans since the early nineteenth century.

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.

The aim of the project is to contribute to the process of archive formation ongoing in Post-Apartheid South Africa through the inclusion of photographs that have been either unacknowledged or excised from the national canon.

On 3 December the Europa Institute organised a debate about the figure of Black Pete. The central theme of the debate was the role which the law can play in deciding the future of Black Pete.

Rossi

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…

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.

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

All kinds of reasons have been put forward for why plants apparently fail to make maximum use of the available light. None of these reasons can explain why after two billion years of evolution they are not black, like industrial photovoltaic solar cells. Are we missing something?

Older children more frequently link Black Pete with a black person. Both younger and older children think positively about him. This is the conclusion of a study conducted by Judi Mesman, Professor of Diversity in Parenting and Development.

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…

The increasing competition in the automotive industry requires the tailored, swift development of technologically sophisticated vehicles. Therefore, the computationally expensive state-of-the-art simulation technologies are combined with optimization algorithms. An example of a real-world optimization…

How is Indian foreign policy made? This special issue of the journal India Review, edited by political scientists Nicolas Blarel (Leiden University) and Avinash Paliwal (SOAS University of London) features a number of interesting case studies that bridge the gap between Foreign Policy Analysis and India’s…

Uncertainty and noise are frequently-encountered obstacles in real-world applications of numerical optimization. The practice of optimization that deals with uncertainties and noise is commonly referred to as robust optimization.

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…

The worldwide protests following the police violence in the United States show how deep-rooted and wide-spread racism is across the world. As an academic institution doing research on law & society, the Van Vollenhoven Institute is very much aware of systemic racism and speaks out in support of these…

When a star gets too close to a supermassive black hole, it is torn apart by strong tidal forces in a tidal disruption event (TDE).

In this thesis new methodologies are developed for the detection and systematic study of radio sources in the early universe. This allows us to gain a deeper understanding of the formation and evolution of galaxies, the activity of supermassive black holes, and the final phase transition of our universe:…

The first photo of a black hole and measuring anxiety in the brain... From 13 until 22 May we're serving a free slice of science with your pizza.

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…

Black Theatre, activist theatre by and for black South Africans, flourished under apartheid. However, according to Francis Rangoajane, the democratisation of South Africa has in no way diminished the importance of this art form. PhD defence 16 November.

The composition Popular Archeology: Volca #1 (for percussion) by composer and ACPA PhD researcher Aart Strootman, has been awarded the Black Pencil in Schokland Prize.

The radio sky harbours both galactic and extragalactic sources of arcminute- to degree-scale emission of various physical origins. To discover extragalactic diffuse emission in the Cosmic Web beyond galaxy clusters, one must image low–surface brightness structures amidst a sea of brighter compact fore-…

Following the Big Bang, structure in the Universe started collapsing under the force of gravity. This resulted in the formation of the first stars, galaxies and clusters of galaxies.

Promotor: W. Jaffe, Co-promotor: K. Meisenheimer