E-Dissertationen: Browsing E-Dissertationen by Classification (DDC) "ddc:520"
Now showing items 21-40 of 244
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Cosmology with the galaxy bispectrum
Yankelevich, Victoria (2019-10-29)The last decades witnessed huge progress in understanding the large-scale structure of the Universe. While homogeneous and isotropic on the largest scales, the matter and galaxy distributions display complex patterns on ... -
Dark matter halos of galaxies studied with weak gravitational lensing
Kleinheinrich, Martina (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 ... -
Deep radio continuum study of NGC 4631 and its Faraday tomography
Mora Partiarroyo, Silvia Carolina (2016-11-29)NGC4631 is a nearby edge-on spiral galaxy with a spectacular radio halo, one of the largest observed among edge-on galaxies. This makes the galaxy an ideal target to study the properties of synchrotron halos, the propagation ... -
Deep, Large Scale Surveys of Star Forming Regions throughout the Milky Way
König, Carsten (2019-02-04)Star formation and the processes involved are not only important to the Milky Way as an astronomical object, but are also crucial to understand our own origin. For instance, only lower-mass stars like our own Sun have ... -
Dense Cores in Galactic Cirrus Clouds
Böttner, Christoph (2005)In this thesis I study the formation and evolution of dense cores in cirrus clouds. Cirrus clouds are diffuse and translucent molecular clouds widely spread within the galaxy. Dense cores in molecular clouds are the locations ... -
The dense interstellar medium and star formation across the nearby galaxies NGC 3627 and NGC 253
Bešlić, Ivana (2023-10-11)The star formation process is an essential aspect of galaxy evolution. Observations of star-forming regions from sub-pc to kpc scales revealed a tight correlation between star formation and the emission of high-critical ... -
Density split statistic in cosmic shear surveys: Generalisations and its application to the Kilo Degree Survey
Burger, Pierre Alexander (2023-03-24)Understanding the formation and evolution of the Universe’s large-scale structure are fundamental in modern cosmology. Currently, the most accurate model to describe the LSS and other observations like the cosmic microwave ... -
A Detailed Study of Galaxy Clusters with Weak Gravitational Lensing and X-rays
Piel, Jennifer Miriam (2012-07-17)Galaxy clusters represent the top of hierarchical structure formation with the largest dark matter halos. Their abundance with respect to mass and redshift can be used to constrain cosmological parameters. The most extensive ... -
Detailed X-ray properties of galaxy groups and fossil groups
Vijaysarathy, Bharadwaj (2015-09-16)Most galaxies in the Universe are aggregated into groups of galaxies, agglomerations of a few 10s of galaxies at most. For long they have been considered to be very similar to clusters, which contain a few 100s of galaxies. ... -
Determination of the Hubble constant from the strong lensing system B0218+357
Mahmoudian, Haniyeh (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 ... -
Dual-Mode Laser for a Photonic Local Oscillator in the Submillimeter Band and The Molecular Composition of an Oxygen-Rich Asymptotic Giant Branch Star
Kim, Hyunjoo (2007)Generation of local oscillator power at Terahertz frequencies with conventional techniques is difficult and expensive. In this thesis, I demonstrate steps towards a THz source using the photonic local oscillator technique ... -
Dust and gas in the MilkyWay: a full-sky view on the multiphase interstellar medium
Lenz, Daniel (2016-11-04)The Milky Way (MW) Galaxy is a unique laboratory to study the evolution of spiral galaxies, offering great sensitivities and angular resolutions with respect to observations of other galaxies. There, the large distance and ... -
The Dusty, Molecular Envelopes of Red Supergiant Stars: VY Canis Majoris as the Archetypal Example
Verheyen, Lies (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 ... -
The Dynamical Ejections of Massive Stars from Young Star Clusters
Oh, Seungkyung (2017-07-21)Massive stars form in star clusters or OB associations which may be expanded clusters. Such stars can be expelled with a high velocity from their birth cluster through a strong close encounter with other cluster members. ... -
Dynamical Studies of the Globular Cluster Systems around the Giant Elliptical Galaxies NGC4636 and NGC1399
Schuberth, Ylva (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 ... -
Early Nucleosynthesis Studies with Quasar Absorption Line Spectroscopy
Erni, Peter (2007)Studying the light of celestial objects in different wavelengths is a fundamental approach and very common in astronomy, where large ground based telescopes and sophisticated high-resolution spectrographs became recently ... -
Efficient implementations of high-resolution wideband FFT-spectrometers and their application to an APEX Galactic Center line survey
Hochgürtel, Stefan (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 ... -
Embedding the DFSZ–Axino in mSUGRA with R–Parity Violation and its implications for Dark Matter
Poletanović, Branislav (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 ... -
Enabling wide-field, high-spatial-resolution fast transient searches on modern interferometry
Chen, Weiwei (2022-04-13)Fast transients reveal the energetic universe to us. They are usually the products of rapid and enormous energy releases. To study the physical nature behind them, we must know the subtle temporal structure of the signal ... -
Envelope inflation in massive stars near the Eddington limit
Sanyal, Debashis (2016-12-21)Massive stars, i.e. those stars with masses more than about 10 times that of the Sun, are important agents for the chemical and dynamical evolution of galaxies. Because of the steep mass-luminosity relation, massive stars ...