Mathematisch-Naturwissenschaftliche Fakultät: Suche
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Study of two radio gravitational lenses: insight into the high-redshift Universe and properties of mass distribution
(2011-10-11)
Similarly to a magnifying glass, a gravitational field deflects light rays that travel through it. This phenomenon, predicted by the theory of General Relativity by A. Einstein (1915), is referred to as gravitational ...
Modeling Gas-Grain Chemistry in Dark Cloud Conditions
(2012-08-23)
I first wrote a gas phase chemical code, which solves for the gas phase composition of an interstellar cloud as a function of time. We used this code to study the abundance ratios between the H3+ ...
Testing X-Ray Scaling Relations with a Sample of Chandra Galaxy Groups and Detailed Analysis of A2244 with Chandra and Suzaku
(2012-08-12)
Groups and clusters of galaxies are valuable tools for cosmology, especially with respect to their mass and other global properties. Individual clusters are also useful to study the complex gravitational and non-gravitational ...
A Detailed Study of Galaxy Clusters with Weak Gravitational Lensing and X-rays
(2012-07-17)
Galaxy clusters represent the top of hierarchical structure formation with the largest dark matter halos. Their abundance with respect to mass and redshift can be used to constrain cosmological parameters. The most extensive ...
Small-scale studies of the Milky Way disc and halo gas with absorption-line spectroscopy
(2012-12-13)
Progressive studies in the last decades have shown that the interstellar medium (ISM) is more complex and dynamic than previously thought. The presence of the small-scale structures, structures on scales below 1 pc, has ...
Physical and Chemical Properties of Protocluster Clumps and Massive Young Stellar Objects Associated to Infrared Dark Clouds
(2012-08-10)
The study of high-mass stars is important not only because of the effects they produce in their environment through outflows, expanding HII regions, stellar winds, and eventually supernova shock waves, but also because ...
Weak gravitational lensing analyses of clusters of galaxies
(2011-04-04)
Comprising the most massive gravitationally bound and relaxed structures in the Universe, galaxy clusters are essential in providing a deeper understanding of the properties of dark matter. Being cosmologically young ...
Star formation in galaxies and star clusters
(2011-07-14)
This thesis is devoted to star formation from galaxy-scales (approx. 10 000 pc) to sub-star cluster-scales (approx. 0.1 pc). I develop and test a new method to derive star formation histories of Galaxies from their star ...
Weak Lensing Mass Determination of Eight X-ray Selected Galaxy Clusters from the 400d Survey
(2011-01-19)
Evolution in the mass function of galaxy clusters sensitively traces both the expansion history of the Universe and cosmological structure formation. Hence, measuring the number density of galaxy clusters as a function of ...
Embedding the DFSZ–Axino in mSUGRA with R–Parity Violation and its implications for Dark Matter
(2011-01-21)
We embed the DFSZ axion in supersymmetry with broken R–parity. As Supersymmetry provides hundreds of free parameters we restrict ourselves to the lepton–number violating scenario in minimal supergravity models with ...