Now showing items 21-40 of 43

• Modeling experiments in helioseismic holography ﻿

(2019-05-29)
This dissertation aims at developing a theoretical framework for the signal and noise in helioseismic holography which is mathematically rigorous and physically meaningful. A main focus of this dissertation is modeling the ...
• Multi-dimensional radiative transfer in circumstellar disks ﻿

(2010-01-14)
In this thesis a radiative transfer model for the simulation of protoplanetary disks was developed. As a basis served the general stellar atmosphere package PHOENIX (Hauschildt et al. 1999). ...
• Multi-wavelength Observations of Coronal Waves and Oscillations in Association with Solar Eruptions ﻿

(2011-08-11)
This thesis presents an observational study of the relationship between flares and filament eruptions, and associated waves and oscillations in flare loops and ambient corona. A detailed ...
• Multifrequenzanalyse eines Samples röntgen- und optisch selektierter Aktiver Galaktischer Kerne ﻿

(2005-02-09)
The current knowledge of Active Galaxies (AGN) as well as new observational facts suggest that sophisticated observational techniques are necessary to advance our view on AGN. In this work ...
• Observations and modeling of polar faculae on the Sun ﻿

(2004-12-21)
In this work the structure and dynamics of polar faculae on the Sun, which constitute an important part of the magnetic solar cycle, were studied by means of high resolution spectropolarimetric ...
• On the Detection of Exomoons in Photometric Time Series ﻿

(2019-09-02)
One of the next big steps forward for exoplanet science would be the detection of moons around extrasolar planets. In this thesis I investigate the exomoon candidate around the exoplanet Kepler-1625 b. I estimate the ...
• On the interplanetary properties and evolution of CME-driven shocks ﻿

(2017-05-10)
This work presents the analysis of eleven CME events which were observed by instruments of the Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI) imaging suite on board the NASA Solar TErrestrial RElations ...
• Photometric variability in the Kepler field ﻿

(2013-09-23)
Measurements of rotation and differential rotation for more than 20,000 active Kepler stars.
• Quiet Sun Magnetic Fields ﻿

(2004-11-03)
The aim of this Thesis is the study of the quiet Sun magnetic fields. They are characterized by weak polarization signals due to their small-scale coverage of the solar surface, but with the availability of new, high-sensitivity ...
• Simulations of the Karlsruhe Dynamo Using the Lattice-Boltzmann Method ﻿

(2005-10-18)
The dynamo mechanism is on the way of understanding. Several numerical simul ations have shown the dynamo mechanism successfully. In recent years dynamo mech anism could be brought down to ...
• Small-scale structures in the upper atmosphere of the Sun ﻿

(2017-06-14)
Context: Numerous small-scale structures with sizes of the order of megameters (Mm), constitute the background for the large-scale structures in the solar atmosphere. Although these features are small, their large ...
• Spectroscopy of Binaries in Globular Clusters ﻿

(2020-05-28)
The natural constants in the universe are adjusted so that dense and massive star forming regions can end up in gravitational bound star clusters, called globular clusters. These objects are found in all galaxies and are ...
• Star-Planet Interactions: Emission Spectroscopy of H$_{3}^{+}$ in Extrasolar Giant Planet Atmospheres ﻿

(2019-08-26)
Extrasolar giant planets (EGP) in a close-in orbit undergo extreme irradiation by their host star. Emission of H$_{3}^{+}$ is expected to support the stabilization of the planetary atmosphere, since the ion radiates in the ...
• Surface reflectance analysis of small bodies on different scales ﻿

(2015-08-11)
The aim of this thesis is to model the surface reflectance of small bodies using  spacecraft data i.e. asteroids Steins and Lutetia. The overall and local variation of brightness  from the surface covers with different ...
• Technologiebezogene Professionalisierung angehender Physiklehrkräfte - Entwicklung und Evaluation eines Lehrkonzepts in der Astrophysik mit digitalen Medien ﻿

(2022-09-09)
This thesis discusses the development and empirical evaluation of a university course in the form of an astrophysics tutorial that focuses on teaching and learning with digital media. Framed by design-based research, an ...
• The search for substellar companions to subdwarf B stars in connection with evolutionary aspects ﻿

(2011-12-14)
The formation and evolution of single hot subdwarf B stars is not entirely understood. Enhanced mass loss during the red giant phase is a prerequisite to explain the very existence of these ...
• The solar wind’s geomagnetic impact and its Sun--Earth evolution -- Predictive models for space weather and the Parker Solar Probe orbit ﻿

(2018-11-06)
This thesis addresses two current topics in solar wind research and space weather. The first study is dedicated to the solar wind's impact on geomagnetic activity and the second study to the estimation of the solar wind ...
• The tilt and twist of emerging solar active regions ﻿

(2022-04-26)
The aim of this thesis is to characterize the tilt and twist of the emerging magnetic field in the solar photosphere, which play an important role in understanding the origin and dynamics of the solar magnetic field. The ...
• Timing of stellar pulsations to search for sub-stellar companions beyond the main sequence ﻿

(2020-08-27)
Stars spend most of their life on the main sequence (MS). But their most substantial changes occur off the MS stage, either before on the pre-MS or beyond at the post-MS phase. Due to very complex and varied dynamical ...
• Towards constraining the solar dynamo with observational studies of the Sun's magnetic field ﻿

(2022-04-26)
A complete understanding of the physical mechanisms responsible for the solar magnetic field is yet to be attained. The origin of the Sun's magnetic field, with its spatio-temporal coherence, is attributed to a dynamo ...