Mathematisch-Naturwissenschaftliche Fakultät: Suche
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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 ...
Weak lensing shape measurement calibration studying effects of stronger shears and cluster contamination for the mass estimation of relaxed galaxyclusters
(2020-09-25)
Weak lensing measurements suffer from well-known shear estimation biases, which can be partially corrected for with the use of image simulations. In this work we present an analysis of simulated images that mimick observations ...
Heterotic Particle Models from various Perspectives
(2012-10-24)
We consider the compactification of heterotic string theory on toroidal orbifolds and their resolutions. In the framework of gauged linear sigma models we develop realizations of such spaces, allowing to continously vary ...
Galactic massive star forming regions near and far: a (sub)millimeter study of the Orion Molecular Cloud 1 and W49A
(2010-09-10)
Massive stars play an important role in shaping the structure of galaxies due to the large energy output during their lifetime. However, because of the short evolutionary time scales, the large extinction toward their birth ...
Weak Lensing Flexion Study
(2010-09-01)
In this thesis, I studied the higher order weak gravitational lensing effect,flexion, and some of its potential applications in cosmology.
Flexion, as a new subject in lensing, has shown its advantages in various ...
Flexion, as a new subject in lensing, has shown its advantages in various ...
Massive star-forming regions across the Galaxy: Initial stages of massive star formation in infrared high extinction clouds and Trigonometric parallaxes to 6.7GHz methanol masers
(2010-07-02)
Star-forming regions trace the spiral structure of the Galaxy. They are regions of increased column density and therefore traced well by the extinction in the mid-infrared based on the Spitzer/GLIMPSE 3.6-4.5 micron color ...
Theoretical Aspects of Cosmic Shear and its Ability to constrain Cosmological Parameters
(2009-03-13)
In the last decade weak gravitational lensing by the large-scale structure of the Universe, also called cosmic shear, has become an important tool to constrain cosmological parameters. Despite this success there remain ...
Environment and Properties of Submillimeter Galaxies
(2009-03-06)
Extra-galactic surveys with large submillimeter bolometer cameras discovered a population of dust obscured starbursting galaxies at high redshifts. These submillimeter galaxies (SMGs) are crucial in the stellar build up ...
Studying Galaxy-Galaxy Lensing and Higher-Order Galaxy-Mass Correlations Using the Halo Model
(2009-06-22)
In recent years, the distribution of galaxies in the Universe could be measured up to large distances and over a significant part of the sky. The analysis of this large-scale structure contains a wealth of cosmological ...