Sökning: "Fysik med inriktning mot astrofysik"
Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Fysik med inriktning mot astrofysik.
1. Bright Needles in a Haystack : A Search for Magnetic Monopoles Using the IceCube Neutrino Observatory
Sammanfattning : The IceCube Neutrino Observatory at the geographic South Pole is designed to detect the light produced by the daughter-particles of in-ice neutrino-nucleon interactions, using one cubic kilometer of ice instrumented with more than 5000 optical sensors.Magnetic monopoles are hypothetical particles with non-zero magnetic charge, predicted to exist in many extensions of the Standard Model of particle physics. LÄS MER
2. Search for a new light boson in meson decays
Sammanfattning : The subject of the presented work lies in the field of experimental particle physics. The main topic is the study of e+ e− pairs from η meson decays. The data sample used in this work was collected by the WASA-at-COSY collaboration in proton-proton collisions at 1.4 GeV kinetic beam energy. LÄS MER
3. The Extremes of Neutrino Astronomy : From Fermi Bubbles with IceCube to Ice Studies with ARIANNA
Sammanfattning : The Fermi bubbles are extended regions of hard gamma-ray emission which were discovered with Fermi-LAT data to exist above and below the Galactic Center. In order to explain the origin of the gamma-rays, different theories are proposed. LÄS MER
4. Atomic Processes in Stellar Atmospheres : Inelastic Collisions and Effects on Late-type Spectra
Sammanfattning : Chemical abundances as measured from stellar spectral lines are often subject to uncertainties due to lack of accurate data for inelastic collisions, which is needed for non-local thermodynamic equilibrium (non-LTE) modelling. For cool stars, understanding of collision processes with electrons and hydrogen atoms is required to achieve high precision measurements. LÄS MER
5. Mass Loss of Evolved Stars : Improving Mass-Loss Rates and Distances
Sammanfattning : In the final stages of their lives, low to intermediate-mass stars enter the Asymptotic Giant Branch (AGB) phase, where they experience significant mass loss through dusty stellar winds. This mass loss is pivotal, not only for the chemical enrichment of the interstellar medium, setting the stage for new stars and planets to form, but also in dictating the evolution and the ultimate fate of the stars themselves. LÄS MER