E-Dissertationen: Search
Now showing items 1-10 of 10
Dynamical Studies of the Globular Cluster Systems around the Giant Elliptical Galaxies NGC4636 and NGC1399
(2011-08-02)
Dark matter studies in elliptical galaxies were long hampered by the lack of suitable dynamical tracers. The advent of 8 m-class telescopes equipped with multi-object spectrographs has made it possible to use globular ...
The Dusty, Molecular Envelopes of Red Supergiant Stars: VY Canis Majoris as the Archetypal Example
(2011-11-15)
Red supergiant stars are surrounded by dusty envelopes, which harbor a multitude of molecules. Often, they are also known to show maser emission. We collect a sample of 88 red supergiants associated with Galactic open ...
High resolution magnetic field measurements in high-mass star-forming regions
(2011-09-22)
Three different scenarios have been proposed to explain the formation of high-mass stars. In one of these scenarios, core accretion, massive stars form through gravitational collapse, which involves disk-assisted accretion ...
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 ...
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 ...
On the origin and nature of brown dwarfs and massive planets
(2011-03-02)
In this thesis the apparent peculiarities of brown dwarfs (BDs) are pointed out which force us to treat them as a population apart from, but yet still related to the stellar population. In particular, the properties that ...
Jets from Spinning Black Holes in Active Galactic Nuclei
(2011-02-08)
Relativistic jets are highly collimated plasma outflows that can be present in extragalactic radio sources, which are associated with active galactic nuclei (AGN). Observations give strong support for the idea that a ...