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

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

This thesis presents the anharmonic infrared spectra of a series of polycyclic aromatic hydrocarbons. Comparisons and characterizations are made based on high-resolution low-temperature gas-phase experimental spectra.

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

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.

Understanding how chemical complexity emerges during star formation requires connecting molecular material preserved in interstellar ices with that observed in the gas phase after protostellar heating begins.

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

The goal of the research presented in this thesis was to explore the chemical space of ruthenium(II) photocages, investigate their ability to host potent chemotherapy drugs, and to red shift the activation wavelength of the most promising PACT candidates to conduct biological studies.

A dense region of a gaseous and dusty cloud collapses to form a protostar surrounded by a disk and an envelope. This thesis uses both observations and models to study physical and chemical conditions of these protostellar systems which are likely where planets start to form.

The Dutch-Japanese made DESHIMA instrument has passed its first practical tests when measuring the distances and ages of distant galaxies. The core of the instrument is a chip the size of two euro coins that measures 49 shades of far infrared light. The developers of the spectrometer publish the results…

This thesis develops a method for direction dependent calibration of the ionosphere in radio interferometric data.

On the largest scale, the Universe resembles a cosmic spiderweb. Most galaxies coexist in small groups within the threads of this web. At the nodes of the threads are enormous groups of galaxies forming the largest structures in the universe still held together by gravity: clusters of galaxies.

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

Promotor: Prof.dr. E.F. van Dishoeck, Prof.dr. F.F.S. van der Tak (RUG)

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: Prof.dr. E.F. van Dishoeck, Co-promotor: S. Bruderer

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-…

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.

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

The formation and evolution of galaxies is fundamentally driven by the formation of new stars out of cold gas.

This thesis is largely an experimental study on the formation of solid-state simple and complex organic molecules in the H2O-rich and CO-rich ice phases of dense interstellar clouds and dark cores.

Complex Organic Molecules (COMs) have been detected in objects across different stages of stellar evolution.

Promotor: J.G.E.M. Fraaije, Co-Promotor: A. Kros

Large areas of space are filled by molecular clouds that consist of gas and dust grains that are the remnants of dead stars. When these clouds start collapsing, the decreasing temperature and increasing density cause gas particles to start accreting onto dust grain surfaces.

Astronomers want to understand the Universe, from the Big Bang to the present day, and what the future will hold. In Leiden they focus on two key questions: ‘How did stars and planets originate’ and ‘How were galaxies and black holes formed in the young Universe?’ A new generation of telescopes – just…

The skin barrier function is provided by the stratum corneum (SC). The lipids in the SC are composed of three lipid classes: ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs) which form two crystalline lamellar structures. In the present study, we investigate the effect of CER chain length…

Barrier function is the natural role of the skin. The lipid matrix present in the outermost layer of the skin, the stratum corneum is important for this function.

The CMCB brings together a diverse range of unique expertise in microbial cell biology. Members of the CMCB investigate both model and non-model organisms, bacteria and archaea, pathogens and non-pathogens.

Metal-based prodrugs based on ruthenium(II) polypyridyl complexes have proven to be very suitable for application in both photodynamic therapy (PDT) and photo-activated chemotherapy (PACT).

The lipids in the uppermost layer of the skin, the stratum corneum (SC), play an important role in the skin barrier function. The three main SC lipid classes are ceramides (CER), cholesterol and free fatty acids.

Promotor: Prof.dr. E.F. van Dishoeck, Co-Promotor: G.J. Herczeg

Stellar feedback is a crucial ingredient in the evolution of galaxies.

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

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?

After 25 years, this December will finally see the launch of the long-awaited James Webb space telescope (JWST). Leiden astronomers are watching with great excitement: not only were they involved in the construction of important instruments on board, but the telescope will also reveal many new secrets…

Astronomer Jos de Boer has received the Chesneau Prize in Nice for his research into so-called protoplanetary disks. The prize is awarded to the best astronomical dissertation in the field of high angular resolution. 'I consider it a good opportunity to talk about my research.'

Promotor: C.U. Keller, Co-Promotor: F. Snik

Psycholinguistic research

Lecture

The Institute Council (IC) provides an important link between the Institute Board, institute committees, and staff groups (i.e. scientific staff, support personnel, permanent and temporary) and student members of the institute. The IC has an important role regarding policies, strategies and other…

Promotor: M.A.G.J. Orrit

The origin and evolution of galaxies are closely linked to many different physical phenomena.

When a star is born in our Galaxy, it is quite likely that it has formed within a massive cluster, which hosts numerous high-mass stars bathing their lower mass neighbours in UV radiation.

Because we cannot directly ask babies about what they know or what they are thinking about, we must find smart and baby-friendly ways to figure it out! Below you can read about the different methods that we typically use in our studies.

In the large gas clouds between the stars, chemical reactions take place under extreme conditions, giving rise to both small molecules, such as water and common salt, as well as large complex molecules that can serve as the building blocks of life. This is known as astrochemistry and it is something…

Recent study led at the Leiden Observatory has observed Orion with unprecedented detail. New data from the Atacama Large Millimeter/submillimeter Array (ALMA) and other telescopes have been used to create this stunning image showing a web of filaments in the Orion Nebula. These features appear red-hot…

The NestWacht project is a Citizen Science collaboration between Science Centre Delft, Naturalis, and the Citizen Science Lab of Leiden University to engage individuals, families and primary schools in Leiden and Delft in scientific research on the impact of climate change on nature in their city, and…

Netherton Syndrome (NTS) is a rare genetic skin disease caused by mutations in the serine protease inhibitor Kazal-type 5 gene, which encodes the lympho-epithelial Kazal-type-related inhibitor. NTS patients have a profound impaired skin barrier function. Because SC lipids play a crucial role in the…

Promotor: P. T. de Zeeuw, Co-promotor: N. Neumayer; G. van de Ven