Promotor: Prof.dr. M. de Jong, Co-Promotor: Dr. A.J. Heijboer

This thesis revolves around the electronic spectroscopy of molecules in the laboratory and the search for the carriers of the diffuse interstellar bands (DIBs).

Promotor: M. de Jong, Co-Promotor: Samtleben

For the first time, scientists have traced back a high-energy neutrino to its source in space. It was produced by a so-called blazar—a supermassive black hole. Researchers from neutrino detector IceCube report this in Science. ‘This is a milestone for neutrino science,’ says physicist Dorothea Samtleben…

In this thesis, I study the formation of large-scale structure and the physics of particle acceleration at large scales (~Mpc).

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.L.V. Linnartz

Promotor: A. Achúcarro Co-promotor: A. Boyarsky

Physicists, including Dorothea Samtleben from Leiden University, are building a giant underwater telescope to unravel the origin of neutrinos and to solve the mystery surrounding dark matter. The first detector has now been installed. Once it is finished, the telescope will be three cubic kilometres…

Dishoeck

The focus of the dissertation "Aspects of cosmic acceleration" is the study of possible mechanisms responsible for the late-time accelerated expansion of the universe.

This thesis focuses on the X-ray spectral analysis of merging galaxy clusters and the plasma code development for future high-resolution X-ray spectroscopy observations.

Het project heeft plaats gevonden in de KM3NeT Nikhef Amsterdam groep onder begeleiding van Dr. D.F.E. Samtleben en Prof.dr.ir. T.H. Oosterkamp. De titel van de presentatie is:"Exploiting cosmic ray showers for time calibration of the KM3NeT detector in the laboratory." De datum van de presentatie…

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

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The theoretical explanation of cosmic acceleration is nowadays one of the biggest puzzles in cosmology.

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

Promotor: Prof.dr. M. Franx, Co-Promotor: Rychard Bouwens

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

Promotor: Jelle S. Kaastra Co-promotor: Jelle de Plaa

In this work the reconstruction of a tau neutrino signal in the KM3NeT detector is discussed.

Promotores: Prof.dr. M. Franx & Prof.dr. P.G. van Dokkum (Yale University)

Lecture

The KM3NeT neutrino detector celebrates the installation of the first string of detectors in the Mediterranean Sea off the French coast. It will measure neutrinos’ spooky spontaneous change in flavor. Leiden physicist Dorothea Samtleben is closely involved in the project.

Alzheimer’s disease is the most common form of dementia. This makes fundamental research on the precise cause of the illness of vital importance. One of the possible suspects is a certain protein filled with iron. Leiden physicist Lucia Bossoni (LION/LUMC) has now developed a new way of investigating…

Determining new protein structures from X-ray diffraction data at low resolution or with a weak anomalous signal is a difficult and often an impossible task.

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

This dissertation provides a comprehensive overview of the grammar of Bantawa, a Kiranti (Rai) language spoken in Eastern Nepal.

Biomolecular X-ray structures typically provide a static, time- and ensemble-averaged view of molecular ensembles in crystals. In the absence of rigid-body motions and lattice defects, B-factors are thought to accurately reflect the structural heterogeneity of such ensembles.

For a number of years, two ‘boxes’ in the Canary Islands and Chile have been scouring the skies for exoplanets that orbit bright stars. PhD candidate Geert Jan Talens helped develop these ‘MASCARA’ telescopes and has made the first discoveries with them. Together with him, we answer the main questions…

In this thesis we study the landscape of gravitational models which modify GR by introducing an additional scalar degree of freedom (d.o.f.) to source Cosmic Acceleration.

Galaxies are often found in clusters, which contain many “red and dead” members that stopped forming stars in the distant past. Now, an international team of astronomers, led by Andra Stroe of Leiden Observatory and David Sobral of Leiden and the University of Lisbon, has discovered that these comatose…

A team of laboratory astrophysicists from Leiden University managed to make glycerol under conditions comparable to those in dark interstellar clouds. They allowed carbon monoxide ice to react with hydrogen atoms at minus 250 degrees Celsius. The researchers publish their findings in the Astrophysical…

Lecture

Promotor: J.W.M. Frenken, Co-Promotor: R. Felici

PhD Defence

The largest galaxies in the Universe feed off cosmic oceans, which helps them grow. This is the presumption of an international team of scientist with two Leiden astronomers, based on observations of the ‘Spiderweb’ galaxy. The researchers published their evidence in Science on 2 December 2016.

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

This thesis contributes to studying primordial cosmology theories and their detectability in future observations.

PhD Defence

The Netherlands Organisation for Scientific Research NWO allocates nearly € 19.5 million to a Dutch cluster that contributes to the development of an X-ray camera and spectrograph for the new European space telescope Athena. Leiden Observatory is one of the members of the cluster.

Promotor: Prof.dr. M. Ubbink

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…

Promotor: Prof.dr. J.W.M. Frenken

Scientists from Leiden and Delft recently discovered old texts using X-ray radiation. The subject was reported in the English newspaper The Guardian.