Radio jets are important to the evoultion of galaxies. However, it is still not fully understood how a radio jet can be triggered.

The thesis deals with the study of giant radio galaxies (GRGs), which are radio galaxies of megaparsec sizes.

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.

We explored how to morphologically classify well-resolved jetted radio-loud active galactic nuclei (RLAGN) in the LOw Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) using machine learning.

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

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

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.

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.

Promotor: Prof.dr. H.J.A. Rottgering, Co-promotor: David Sobral

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

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.

Within the field of astronomy, understanding how galaxies grow and evolve from the Big Bang to the present day is a challenging and complex question.

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: H.J.A. Röttgering, Co-promotor: M. Haverkorn

Labbe

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: M. Franx, Co-Promotor: I.F. Labbé

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: Koen Kuijken Co-promotor: Henk Hoekstra

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

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

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

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

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

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…

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…

Promotores: F.H. van Lunteren, F.P. Israel

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.

It has now been well established that shocks and turbulent motions in the intra-cluster medium (ICM) generated through cluster mergers can produce large-scale synchrotron emission.

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

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.

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

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

The largest structures in the Universe are clusters of galaxies. Each can contain hundreds to thousands of galaxies.

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.

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

Galaxies form and live inside dark matter haloes. As a consequence, they are exposed to the tidal fields generated by the surrounding matter distribution: this imprints a preferential direction to the galaxy shapes, which leads to a coherent alignment on physically close galaxies, called intrinsic a…

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

Promotor: J. Schaye

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

This thesis focuses on the study of transient and variable radio sources in the universe.

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

Forming at the nodes of the Cosmic Web and growing hierarchically via mass accretion, galaxy clusters are the largest virialized halos in our universe, composed of dark matter (DM; ≥85%), ionized hot plasma in the intracluster medium (ICM; ≥10-15%), and galaxies (≥1-5%).

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…

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

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.

In this thesis, I studied the origin and evolution of the non-thermal radiation in merging galaxy clusters.

Galaxy intrinsic alignments induce a major astrophysical contamination to weak gravitational lensing measurements and need to be modelled and mitigated when extracting cosmological information from such measurements.