Sökning: "NATURVETENSKAP Fysik Astronomi och astrofysik"
Visar resultat 6 - 10 av 470 avhandlingar innehållade orden NATURVETENSKAP Fysik Astronomi och astrofysik.
6. Spectral Properties of Type Ia Supernovae and Implications for Cosmology
Sammanfattning : Type Ia supernovae can, for a short period of time, reach the same brightness as an entire galaxy. They are responsible for the creation of a large fraction of all heavy elements and can be used, as standard candles, to prove that the expansion of the universe is accelerating. Yet, we do not fully understand them. LÄS MER
7. Magnetic fields around massive protostars as traced by masers and dust emission
Sammanfattning : It is not fully clear how the magnetic field acts during the first stages of star formation. A possible way to clarify its role is to observe the polarized light coming from masers and thermal dust emission. LÄS MER
8. Gravitational perturbations in plasmas and cosmology
Sammanfattning : Gravitational perturbations can be in the form of scalars, vectors or tensors. This thesis focuses on the evolution of scalar perturbations in cosmology, and interactions between tensor perturbations, in the form of gravitational waves, and plasma waves. LÄS MER
9. Regolith Properties of Mercury Derived from Observations and Modelling
Sammanfattning : The properties of Mercury's regolith have been investigated at optical and near-infrared wavelengths with high-resolution imaging, photometric, and spectroscopic observations with the Swedish Vacuum Solar Telescope and the Nordic Optical Telescope. A new global optical map at a spatial resolution of 200 km shows that the well known (from Mariner 10) and poorly known hemispheres are indistinguishable with respect to the distribution, number density, and morphological parameters of bright albedo features. LÄS MER
10. Theoretical Atomic Spectroscopy of Earthbound and Stellar Plasma
Sammanfattning : Motivated by spectroscopic analysis of astrophysical and laboratory plasma, this thesis concerns the fundamental structure and spectral properties of atoms and their ions. The multiconfiguration Dirac-Hartree-Fock (MCDHF) method is used to predict the emission or absorption of radiation, by atomic systems in general, and of heavy and highly charged ions in particular. LÄS MER
