Labbe

Promotor: J. Schaye

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

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

Cosmic mist, first-generation stars and state-of-the-art computer simulations made clear that distant galaxies are much more than just simple dots in the sky. By investigating galaxies from the past, astronomer Jorryt Matthee from Leiden Observatory hopes to answer questions about the origin of galaxies,…

Promotores: Prof.dr. M. Franx, Prof.dr. M. Kriek (Univ. of California at Berkeley)

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

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

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

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…

How did galaxies form? How did galaxies evolve?

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.

Promotor: Prof.dr. J. Schaye, Co-promotor: Marcello Cacciato

PhD Defence

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

PhD Defence

PhD Defence

Deep observations made with the MUSE spectrograph on ESO’s Very Large Telescope have uncovered vast cosmic reservoirs of atomic hydrogen surrounding distant galaxies. The exquisite sensitivity of MUSE allowed for direct observations of dim clouds of hydrogen glowing with Lyman-alpha emission in the…

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…

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

Promotor: Koen Kuijken Co-promotor: Henk Hoekstra

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, Co-promotor: David Sobral

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.

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

This thesis explores the theoretical and observational properties of distant massive galaxies that harbour active black holes in their centres and shine brightly at radio wavelengths.

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

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.

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…

Rossi

Researchers at Leiden Observatory study the fundamental physics that creates structure in the Universe. These processes collect matter into galaxies and gas into stars. With the use of powerful telescopes and advanced calculations and computer simulations, Leiden astronomers seek to understand the origin,…

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.

Researchers at Leiden Observatory study the fundamental physics that creates structure in the Universe. These processes collect matter into galaxies and gas into stars. With the use of powerful telescopes and advanced calculations and computer simulations, Leiden astronomers seek to understand the origin,…

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.

This thesis investigates the structural evolution and assembly of galaxies since the first few billions years after the big bang.

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…

Astronomers led by Pieter van Dokkum have discovered a galaxy that barely contains any dark matter, which actually proves that dark matter does indeed exist. The research results will be published this week in Nature.

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

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…

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.

Promotor: H.J.A. Röttgering, Co-promotor: G.K. Miley

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

Galaxies in the early universe are shrouded in a kind of mist: a cloud of hydrogen. With galaxies in the later universe this mist has disappeared. Astronomer Jorryt Matthee has made the first images of this dissipating mist. PhD defence 19 September.

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

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.

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

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.

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.