Promotie: mw. S. Vegetti, 14.45 uur, Academiegebouw, Broerstraat 5, Groningen
Proefschrift: Quantifying mass substructure in early-type galaxies
Promotor(s): prof.dr. L.V.E. Koopmans
Faculteit: Wiskunde en Natuurwetenschappen
Contact: Simona Vegetti, e-mail: firstname.lastname@example.org
Quantifying mass substructure in early-type galaxies
Measuring the Cold Dark Matter (CDM) substructure mass function represents a key test of the CDM paradigm and provides an important step forward in understanding the physical properties of dark matter. Because of the predicted large total mass-to-light ratio of these substructures, gravitational lensing provides a unique opportunity to detect them. In this Thesis I have presented a new adaptive-grid method that based on a Bayesian analysis of the surface brightness distribution of highly magnified Einstein rings and arcs allows to identify and precisely quantify mass substructure in gravitational lens galaxies. I have also developed a Bayesian formalism to statistically interpret mass substructure detections and obtain constraints on the major properties of galaxy subhaloes such as the dark matter mass fraction in subhaloes and the subhalo mass function. I then applied this technique to the analysis of the SLACS lens SDSSJ0946+1006, which has led to the discovery of a very high mass-to-light ratio satellite at redshift z=0.222. With the lens system SDSSJ120602.09+514229.5, having a luminous substructure, I showed that the method can indeed detect substructure in lens galaxies and measure important properties such as the substructure mass and tidal radius. Finally, I demonstrated that high-quality infrared images from Keck laser guide star adaptive optics observations are equally sensitive to substructure and, under certain conditions, can recover the main lens and the substructure parameters equally well as optical data sets from the Hubble Space Telescope ACS and NICMOS.
The University of Groningen established the Ben Feringa Impact Award to highlight the exceptional achievements of researchers and students in the field of knowledge utilization.
The Northern Netherlands region is setting up the AI Hub Northern Netherlands, a new network organization that is bringing together companies, knowledge institutions and other organizations that work with artificial intelligence (AI).
Our climate is changing and not enough has yet been done to prevent a rise in temperature. Humanity must adjust to the consequences of climate change, through climate adaptation. The University of Groningen’s Campus Fryslân and Frisian water board...