Hot astrophysical plasma is ubiquitous in the Universe, from comets in our Solar system to the largest scale structures -- the cosmic web filaments. These hot plasmas, with the temperature of a few millions of degrees, are often observed in the X-ray wavelength range.

Birds sing to be heard, but how do they cope with increasing noise levels? Which species persist in cities and why? And do they thrive or suffer in the urban soundscape?

Dark matter is one of the biggest mysteries of the Universe. Its properties cannot be explained with the known laws of physics and elementary particles.

When galaxies collide, do the black holes at their centre form a supersized black hole? This is what we think happens, but it's not as simple as that, according to Simon Portegies Zwart. Zwart, computer scientist and astronomer, has been awarded a VICI grant to research this phenomenon.

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…

This thesis has shed light on some of the ways in which the local electrolyte composition can differ from the bulk and how these changes in the local reaction environment can determine the activity and/or selectivity of two important electrocatalytic reactions, namely, electrochemical CO2 reduction…

Planets are formed in disks of gas and dust around young stars.

The study of orchid flowers, fruits, and inflorescences is crucial due to the remarkable diversity of orchid species and their unique adaptations to pollinators and seed dispersers. However, our understanding of the evolution and development of these organs within the orchid family remains limited.

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.

Three projects with Leiden researchers are to receive a subsidy from NWO for the construction or renovation of large-scale research facilities. They will be working on electron microscopy, an X-omics initiative and an X-ray telescope. The projects are part of the National Roadmap for Large-Scale Scientific…

In Slaving Zones: Cultural Identities, Ideologies, and Institutions in the Evolution of Global Slavery, fourteen authors—including both world-leading and emerging historians of slavery—engage with the ‘Slaving Zones’ theory.

In 2015, Jorryt Matthee thought he discovered an extremely distant galaxy called CR7, which lacked elements heavier than helium. Three years later, he shows with measurements using the ALMA telescope that the galaxy does have carbon after all, and even in normal concentrations. The American Astronomical…

Plants produce an astonishing variety of secondary metabolites (SMs) which are thought to play vital roles in the fitness of plants through ecological interactions.

Responsible Research and Innovation (RRI) implies that societal actors (researchers, citizens, policy makers, business, third sector organisations, etc.) work together during the whole research and innovation process in order to better align both the process and its outcomes with the values, needs and…

Pulsars were first discovered in 1967 and since then the population has grown and expanded over several wavelengths.

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…

A team of Leiden astronomers used the latest set of data from ESA’s Gaia mission to look for high-velocity stars being kicked out of the Milky Way, but were surprised to find stars instead sprinting inwards – perhaps from another galaxy.

Using the MUSE instrument on ESO’s Very Large Telescope in Chile, an international team of scientists, including many Leiden astronomers, have conducted the deepest spectroscopic survey ever. They focused on the Hubble Ultra Deep Field, measuring distances and properties of 1600 very faint galaxies…

PhD defence

An international team of astronomers, including Leiden's Maciej Bilicki, has discovered an enormous supercluster of galaxies. The supercluster had previously been overlooked because it was obscured by our own Milky Way. The researchers are publishing their findings in the Monthly Notices of the Royal…

An international team of astronomers that includes researchers from Leiden has discovered the most distant galaxy yet. The galaxy, called EGS8p7, is 13.23 billion light years away from Earth and already existed when the universe was only 550 million years old.

Evolution is all around you every day. This is the message of a Massive Open Online Course (MOOC) of Leiden University and Naturalis that is offered free of charge to anyone interested.

Media all around the world reported about it: the most detailed images yet seen of galaxies, shot by radio telescope LOFAR. The international team behind these amazing results were led by Leah Morabito at Durham University and included three talented Leiden astronomers.

Certain cichlid fish in Lake Victoria seem to have adapted super-fast to changing circumstances. Dr Frans Witte from the Integrative Zoology section has been awarded an NWO subsidy (approx. € 240,000) to carry out PhD research into the rapid changes apparent in this fish species.

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…

The explosive radiation and diversification of the advanced snakes (superfamily Colubroidea) was associated with changes in all aspects of the shared venom system. Morphological changes included the partitioning of the mixed ancestral glands into two discrete glands devoted for production of venom ormucous…

Promotores: Prof.dr. P.M. Brakefield, Prof.dr. B.J. Zwaan (Wageningen Universiteit)

Promotor: Prof.dr. E.F. Smets, Co-promotor: Dr. V.S.F.T. Merckx

Dwarf satellite galaxies in the Milky Way perform different dances than researchers initially expected. Marius Cautun from Durham University received a Marie Curie grant to unravel the mysteries of this orbital dance. October 1st 2018 he will start his research at the Leiden Observatory.

How did digital intermediality symbolise and facilitate the transfer of content from popular culture into policy statements and vice versa in the period between 1945 and the new millenium?

A global biological study has provided the most direct evidence to date that humans, and specifically cities, are the drivers of evolutionary change on Earth. Leiden University, Naturalis and the Municipality of Leiden worked on and helped fund the study.

ESA’s Gaia mission has produced the richest star catalogue to date, including high-precision measurements of nearly 1.7 billion stars and revealing previously unseen details of our home 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?

An international team of astronomers, with researchers at Leiden Observatory playing a leading role, has mapped the fuel for galaxy formation in the iconic Hubble Ultra Deep Field. The results of the research have been accepted for publication in The Astrophysical Journal.

Research at Leiden Observatory spans the full width of modern astrophysical enquiry. It is based on observation, theory, simulation, and experiment. Two broad clusters characterize the ongoing research. Within each theme, researchers carry out their personal and specialized research programme. The two…

By a stroke of luck, a team led by Dutch PhD student Martijn Oei has discovered a radio galaxy of at least 16 million lightyears long. The pair of plasma plumes is the largest structure made by a galaxy known thus far. The finding disproves some long-kept hypotheses about the growth of radio galaxie…

Within the two-year Astronomy master’s programme, you can choose from seven specialisations, ranging from fundamental or applied astronomy research in cosmology, instrumentation or data science, to combinations of astronomy research with education, management or science communication.

In 2018, astronomer Jorryt Matthee won the C.J. Kok Jury Prize for the best dissertation of the Faculty of Science. He succeeded in finding a number of rare galaxies from the early Universe. One of them received the same initials as football player Cristiano Ronaldo: CR7.

The solar system was formed approximately 4.56 billion years ago. Despite the numerous theories that have been developed over the years, the formation and evolution of the solar system still remain unclear.

I have studied the hot, diffuse gas around and between galaxies. Specifically, I have used the EAGLE numerical simulations of galaxy formation to predict the properties of this gas, and I have used those properties to predict specific observables: soft X-ray absorption and emission lines.

This project combines an extensive new open database on linguistic distributions, spatial modelling and areal linguistics in order to disentangle the roles of social and environmental factors on the emergence of linguistic diversity patterns of South America.

Promotor: K.H. Kuijken

The Astronomy and Data Science master’s specialisation at Leiden University combines advanced Astronomy courses with relevant courses from the Computer Science programme at Leiden University.

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:…

Supervisor: S.F. Portegies Zwart Co-Supervisor: A.G.A. Brown

Promotor: Prof.dr. P.G.L Klinkhamer