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

Promotor: Prof.dr. E.F. van Dishoeck, Co-Promotor: M.R. Hogerheijde

Wetenschappers bij de Leidse Sterrewacht onderzoeken de oorsprong van sterren en hun planetenstelsels. Ze detecteren en karakteriseren planeten rondom andere sterren (exoplaneten). Ze onderzoeken hoe sterren en planeten ontstaan. En ze volgen moleculen van interstellaire wolken tot planetenstelsels…

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

In this thesis chemical and physical processes in the ice mantles on interstellar dust grains are studied.

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

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

To address the fundamental questions of how life on Earth emerged and how common life may be in the Universe, it is crucial to know the chemical composition of the planet-forming material.

Sobral

Galaxies form and evolve through close interaction with their surroundings. As a result, the heavy elements ('metals') that are synthesized in stars, are found both inside and outside galaxies.

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…

This thesis investigates how galaxies form and what diversifies the evolutionary histories of galaxies.

My work focuses on a class of astronomical objects called protoplanetary disks.

Promotor: F.P. Israel, Co-Promoter: R. Meijerink

OB associations are loose groups of young, massive stars. They constitute the last stage of the massive starformation process, and the context in which new stars are formed.

We investigate the buildup of galaxies from various vantage points. The first two chapters focus on the stellar content of galaxies, especially the distribution of stellar masses at birth and potential variations therein in various galactic environments.

Promotie

Lezing

Promotor: J. Schaye

Promotor: Prof.dr. E. F. van Dishoeck

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

Promotores: Prof.dr. J. Schaye & Prof.dr. C. Steidel (California Institute of Technology)

Promotores: Prof.dr. F.P. Israel, Prof.dr. P.P. van der Werf

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.

The work presented in this thesis is based on ALMA surveys of protoplanetary disks in three star-forming regions: Lupus, OMC-2, and NGC 2024.

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

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.

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

Promotor: Prof.dr. A.G.G.M. Tielens, Prof.dr. C. Dominik (UvA)

Promotores: Prof.dr. E.F. van Dishoeck, Prof.dr. C.P. Dullemond

Promotores: Prof.dr. A.G.G.M. Tielens, Prof.dr. L. Kaper (UvA)

Promotores: Prof.dr. A.G.G.M. Tielens, Prof.dr. L.B.F.M. Waters (UvA), Prof.dr. C. Dominik (UvA)

To study how planetary systems come into existence we study much younger systems still in formation.

The thesis explores how interstellar chemistry evolves as a function of time and changing physical architectures during the formation of stars.

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

Promotores: Prof.dr. J. Schaye, Prof.dr. S.D.M. White (MPA Garching)

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

Sterrewacht Leiden is het sterrenkundig instituut van de Faculteit der Wiskunde en Natuurwetenschappen van de Universiteit Leiden.

Galaxies are environments where gas coalesces, cools, and is converted into stars. However, it remains unclear the exact mechanisms through which galaxies acquire, redistribute and lose their gas.

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

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

Promotor: G.P. van Wezel

This thesis examines the link between simple molecules and the underlying structure and chemistry within protoplanetary disks - the birthplaces of planets.

The high velocity tail of the total velocity distribution of stars provides essential insight into fundamental properties of the Galaxy.

Promotie

Promotie

Promotor: Roeland M.H. Merks