This research delves into a region of space known as the interstellar medium (ISM), which is essentially the area between the stars filled with gas and dust.

Many galaxy clusters exhibit bright diffuse radio emission that traces the underlying structure of the intracluster medium (ICM).

We explored the Universe using weak gravitational lensing, a phenomenon that occurs when light from distant galaxies is bent by the gravitational fields of closer cosmic objects, much like how a lens distorts light.

Het Leids Astronomisch Dispuut Frederik Kaiser is een vereniging die zich inzet voor de studenten die in Leiden sterrenkunde studeren. Daarnaast zijn ze ook erg betrokken bij de publieksactiviteiten in de Oude Sterrewacht en helpen ze bij de ontwikkeling en uitvoering van andere projecten in het geb…

The focus of the dissertation

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.

Even though more than 4000 extra-solar planets are known today, only a small fraction of these has been captured in an image. To better understand the planet formation mechanisms in solar-like environments we started the Young Suns Exoplanet Survey (YSES).

A large diversity of exoplanetary systems has been found, but it is still unclear what drives this diversity.

In this thesis, we present new laboratory data of interstellar dust analogues.

Carbonaceous asteroids preserve a record of early solar system processes, where minerals and organic molecules, like polycyclic aromatic hydrocarbons (PAHs), offer clues to planetary evolution and prebiotic chemistry.

Promotor: J. Schaye

In astronomy, the interpration of observations and measurements plays a crucial role: we rely purely and fundamentally on the information that reaches us as observers. And 80% of all matter in the universe is undetectable directly.

Promotor: K. Kuijken, Co-Promotor: H. Hoekstra

Promotor: Prof.dr. A.G.G.M. Tielens

Stars and planets form within cold, dense clouds of gas and dust drifting through interstellar space. Although dust makes up only a small fraction of this material, it plays a key role in shaping the chemical evolution of these environments.

Nowadays, it is well known that hydrogen and helium (and small traces of lithium and beryllium) were created shortly after the Big Bang, while the heavier elements are created in the cores of stars at different evolutionary stages. When these stars explode as supernovae, they expel metals synthesised…

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.

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…

Understanding how galaxies form, interact, and evolve comes largely from comparing theory predictions with observational data. Numerical simulations of galaxies provide the most accurate approach to testing the theory, as they follow the non-linear evolution of gas and dark matter in great detail and…

Patterned detectors are an existing technology that can be found in almost all color cameras.

Promotor: Prof.dr. K.H. Kuijken, Co-Promotor: H.Hoekstra

Astronomical observations of cold regions in the universe show a rich inventory of ices. Part of these ices may end up on planets like our own, but in that journey they will be exposed to considerable amounts of radiation.

Low-mass main-sequence stars like our Sun are continuous sources of outflowing hot magnetised plasma. In the case of the Sun, this is known as the solar wind, whereas for other stars they are called stellar winds.

Promotor: Christoph U. Keller, Co-promotores: Matthew A. Kenworthy, Frans Snik

Until the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial efforts have been made to explore these strange new worlds through spectroscopic analyses of their atmosphe…

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

In this thesis, the research focuses on the properties of dark matter and dark matter haloes and how they connect with the galaxies we can observe in the Universe.

This thesis is about the study of hydrocarbons via infrared spectroscopy.

One of the most important puzzles in modern astrophysics is the nature of dark matter.

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.

The focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed.

Of all the mass in our Universe, 80% is thought to consist of a hypothetical and invisible substance called dark matter (DM).

Promotor: Prof.dr. S.F. Portegies Zwart

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-…

Three major cosmology-focused missions are planned for the next decade: the Euclid space telescope, the Vera C. Rubin Observatory in Chile, and the Nancy Grace Roman Space Telescope.

Outflows are crucially important for the gas budget and evolution of luminous star-forming galaxies and AGNs, with observed mass outflow rates of the same order as the star formation rate. Greater star formation and black hole growth lead to more intense feedback and outflows, resulting in self-regulated…

Multiple stars, that is two or more stars composing a gravitationally bound system, are common in the universe.

When observing star-forming galaxies, we are not only seeing stellar light, but we also see how this interacts with galactic gas and dust. This thesis contains studies of the stellar, nebular and dust properties of low mass star-forming galaxies.

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.

Promotor: Prof.dr. H.J.A. Rottgering

Promotor: Prof.dr. S. Portegies Zwart

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.

More than 5,000 exoplanets have been found over the past couple of decades. These exoplanets show a tremendous diversity, ranging from scorching hot Jupiters, common super-Earths, to widely separated super-Jupiters on the planet/brown dwarf boundary.

Promotor: E. F. van Dishoeck, Co-promotor: C. Walsh

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.

This thesis discusses the physical and chemical processes than influence the composition of forming planets.

A century ago, it was unclear whether the stars in the sky were clustered in groups, or widely spread in the universe.

This research focuses on the distribution of chemical elements in protoplanetary disks, the birthplaces of planets. These disks form around young stars and contain gas and dust, from which planets grow. Ice plays a crucial role in planet formation, aiding the clumping of dust particles and influencing…

Promotor: J.S. Kaastra Co-promotor: E. Constantini

Promotor: I. A. G. Snellen, Co-promotor: M. A. Kenworthy