The thesis set out to investigate the nature and genesis of the peculiar class of X-shaped radio galaxies. X-shaped sources are puzzling because of the extremely low number of objects of that type. Three scenarios were ...

The aim of this thesis is to investigate the first overtone band emission of CO from the peculiar B[e] star MWC 349. With the United Kingdom Infrared Telescope (UKIRT) in Hawaii, low resolution observations were made to ...

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 ...

We have observed the Quasar 3C345 with VSOP and the VLBA at four different frequencies (1.6GHz, 5GHz, 22GHz and 43GHz), making a total of 24 epochs, from 1997.40 to 1999.69. This study, combined with previous observations, ...

Starting from measurements of the linear polarization of the radiation emitted by celestial objects it is possible to estimate some physical parameters of the source. For example, magnetic field intensities and directions ...

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 ...

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 ...

High resolution maps of the Sunyaev-Zel'dovich effect in clusters of galaxies offer a powerful tool for studying physics in clusters and cosmology. The Hundred Millikelvin Bolometer Array (HUMBA) for 2 mm continuum observation ...

Understanding the star-forming procedure is one of the most important topic in astrophysics. One of the most unexplored fields in the star-forming theories is magnetic field. Magnetic field is believed to play an important ...

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 ...