Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Peter, Hardi Prof. Dr."
Now showing items 1-17 of 17
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Stellar Activity and Radial Velocities in M Dwarfs
(2024-07-17)Stellar activity is one of the principal obstacles to achieving sub 1 m/s radial velocity precision in exoplanet detection surveys. Understanding how stellar activity affects the stellar environment is crucial to mitigating ... -
High Precision Spectroscopy of the Solar Surface
(2024-06-17)Context: High-precision spectroscopy of the resolved solar surface provides benchmark observations for a vast field of stellar research. The solar spectrum exhibits variations from the disc centre to the limb. Observing ... -
Global scale magnetic field extrapolation in the solar corona using a Yin Yang grid
(2024-05-06)The solar magnetic field significantly influences and structures the solar coronal plasma as magnetic forces are the dominant forces within the solar corona. Therefore, an in-depth understanding of the phenomena that occur ... -
Small-scale dynamo in cool main-sequence stars
(2023-04-13)Cool stars have an outer convection zone which can produce magnetic fields. These fields have a large scale component that is dependent on the solar cycle, as well as small-scale component largely independent of the cycle. ... -
A coronal loop in a box: From energy generation to coronal emission
(2023-03-17)The corona is the outer atmosphere of the Sun. It contains an abundance of bright arcs that consist of hot plasma trapped by the magnetic field. These coronal loops are heated to temperatures far surpassing the solar surface ... -
Strong magnetic fields and unusual flows in sunspots
(2023-02-06)This thesis presents a study of sunspots, which are the most prominent features observed on the solar surface. Their structure is governed by the magnetic field. The umbra and penumbra of sunspots harbor different strengths ... -
Modelling the corona of stars more active than the Sun using 3D MHD simulations
(2021-06-10)Cool stars like our Sun are surrounded by coronae with temperatures up to several million Kelvin. After decades of research, there has been no definite explanation as to why the coronae of stars are several orders of ... -
High resolution scattering spectropolarimetry of the quiet solar photosphere
(2021-01-14)In this thesis we investigate small-scale scattering polarization signals in quiet, internetwork (IN) regions of the lower solar atmosphere. Small-scale polarization signals are inherently hard to observe due to their ... -
Analysis of Space Weather Impacts on the Terrestrial Ionosphere and Development and Testing of a Coronagraph for Space Weather Forecasts
(2020-07-22)The ionosphere is a conductive layer of the Earth's atmosphere, characterised by the presence of free electrons. Through interaction with electromagnetic waves, it influences a wide spectrum of radio wave communications, ... -
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 ... -
Slender Ca II H fibrils observed by SUNRISE/SuFI
(2018-04-24)This thesis is devoted to analyzing the morphological and oscillatory properties of slender \caiih{} fibrils (SCFs) in the lower solar chromosphere. The aim of this study is to deepen our understanding of the physical ... -
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 ... -
Magnetohydrodynamic Simulation of Reconnection in Turbulent Astrophysical Plasmas
(2016-08-31)Turbulence is ubiquitous at large-Reynolds-number astrophysical plasmas like in the Solar corona. In such environments, the turbulence is thought to enhance the energy conversion rate by magnetic reconnection above ... -
Coronal dynamics driven by magnetic flux emergence
(2015-11-09)The corona is the Sun’s outer atmosphere which is more than 100 times hotter than the solar surface. It can be brilliantly observed in the extreme-ultraviolent (EUV) and soft X-ray passbands. What heats the corona is one ... -
Analysis of small scale solar magnetic fields using Hinode SOT/SP
(2014-07-23)This thesis presents an analysis of small magnetic structures found in the solar photosphere. All the work presented in the following chapters is primarily based on data obtained from the spectropolarimeter aboard the ... -
Observationally driven 3D MHD model of the solar corona above a magnetically active region
(2014-07-15)Context: The corona of the Sun can be observed since 1932 with instruments occulting the solar disc. Only few years later it became clear that the corona is way hotter than the visible solar surface and since then, the ... -
The response of the corona to different spatial distributions of heat input
(2014-04-09)Explaining the existence of the million degree corona on top of the much cooler Solar surface has provided scientist with a challenge for a several decades. It is not possible for a cooler object to heat something that ...