The Faculty of Mathematics and Natural Sciences: Search
Now showing items 1-10 of 197
Multi-frequency analysis of intraday variable radio sources
(2003)
Active Galactic Nuclei (AGN) are known to show significant flux density variability across the whole electromagnetic spectrum on a wide range of time scales, from years to less than one day. In the radio regime, variability ...
A noise reduction method based upon statistical analysis for the detection of weak signals in discrete data
(2003)
While searching sets of discrete data contaminated heavily by noise for weak signals of correlated data points we have made use of statistic quantities to detect correlations between data points. The signal consists of ...
Lidarbeobachtungen der polaren Atmosphäre: Wolken und Wellen – Phänomene und Mechanismen
(2003)
Since 1997 the Bonn University Institute of Physics operates a Rayleigh/Mie/Raman lidar on the Esrange near the Swedish city of Kiruna north of the Arctic circle. During seven winter and six summer campaigns a large amount ...
Dark matter halos of galaxies studied with weak gravitational lensing
(2003)
The main goal of this thesis is to investigate the dark matter halos of galaxies. Current theories of galaxy formation predict that galaxies are embedded in large dark matter halos with much larger extents than the visible ...
Spiral Galaxies with Thick Box/Peanut Bulges
(2003)
The close connection between bars and box/peanut-shaped bulges is observationally and theoretically supported. However, for the class of thick box/peanut-shaped bulges an environmental hypothesis instead of an internal ...
Asymmetries of Radio Galaxies
(2003)
In this work, we have studied the asymmetries of radio galaxies which are known to be related to the jet-asymmetry. They are the depolarization asymmetry and the spectral index asymmetry. <br /> The first part of the thesis ...
Measurement of the Strangeness Spectral Function and the Mass of the Strange Quark in Hadronic τ Decays with the Opal Detector
(2004)
Tau lepton decays with open strangeness in the final state are measured with the OPAL detector at LEP to determine the strange hadronic spectral function of the t lepton and the mass of the strange quark. The decays ...
Proper Motions in the Local Group
(2004)
In this thesis, the proper motions of two Local Group galaxies, namely M33 and IC10. The proper motions were measured by phase-referencing Very Long Baseline Interferometry (VLBI) observations of water vapour masers in the ...
The Huygens Doppler Wind Experiment: a Titan Zonal Wind Retrieval Algorithm
(2002)
The Cassini/Huygens mission to Saturn, a joint venture of NASA and ESA, was launched on 15 October 1997 from Kennedy Space Center, Cape Canevaral, Florida (USA) and will reach its destination in July 2004. The Huygens Probe ...
A Tale of Two Wide Separation Gravitational Lenses
(2008)
<p>Wide separation gravitational lens systems are good candidates to probe the matter (luminous+dark) distribution in massive halos. Investigation of two wide separation lens systems is carried out. MG 2016+112 is a quadruply ...