E-Dissertationen: Search
Now showing items 21-30 of 111
Cosmic Shear and the Intrinsic Alignment of Galaxies
(2010-11-12)
Cosmology has recently entered an era of increasingly rich observational data sets, all being in agreement with a cosmological standard model that features only a small number of free parameters. One of the most powerful ...
New aspects of star cluster physics
(2010-07-22)
Star clusters are the birth-sites of both low- and high-mass stars and can be considered to be the building blocks of galaxies. Therefore, the understanding of the formation, evolution, and death of star clusters is of ...
Flux Density and VLBI Measurements of the IDV Source 0917+624
(2010-03-29)
Extragalactic compact flat spectrum radio sources are known to be highly variable and about 30% of them show intra-day variability (IDV). The quasar 0917+624 was known to show prominent IDV behaviour from the time it was ...
Determination of the Hubble constant from the strong lensing system B0218+357
(2013-07-08)
Gravitational lensing and particularly strong lensing provide variety of subjects to study such as galaxy evolution, substructure detection in galaxies or cluster of galaxies. Also strong lensing enables us to derive the ...
Efficient implementations of high-resolution wideband FFT-spectrometers and their application to an APEX Galactic Center line survey
(2013-06-13)
Spectroscopy has been a major technique in radioastronomy for decades and spectrometers are used in a wide range of radioastronomical applications. With more stable receivers that are wider in bandwidth, spectrometers are ...
The formation and the stellar populations of dwarf galaxies
(2013-11-14)
Ultra-compact dwarf galaxies (UCDs) are stellar systems with masses similar to those of dwarf elliptical galaxies (dEs), but with characteristic radii that are about a factor of ten smaller than those of dEs. One of the ...
Multi-Wavelength Observations of the High-Mass Star Forming Complexes W33 and DR 21
(2013-12-18)
High-mass stars play a key role in shaping the Universe. Stars with masses above 8 M_sun have a huge impact on the energy budget of galaxies, through their stellar winds, expanding HII regions, outflows, and supernova ...
Multi-wavelength studies of pulsars and their companions
(2013-09-25)
Neutron stars are the degenerate relic cores of massive stars formed in the aftermath of a supernova explosion. Matter in their centes is believed to be condensed at densities as high as ten times that found in atomic ...
Variability of radio and TeV emitting X-ray binary systems: The case of LS I +61°303
(2013-09-09)
X-ray binaries contain a compact object, a black hole or a neutron star, and a normal companion star. An exclusive club of only ∼5 sources, also emits in radio and in gamma-rays. The nature of these gamma-ray binaries is ...
Molecular line emission in asymmetric envelopes of evolved stars
(2014-07-03)
Stars with initial masses of 0.8 < M⋆ < 9M⊙ eject most of their mass when evolving along the asymptotic giant branch (AGB) phase. The ejected material eventually cools down, which leads it to condensate ...