Search for dissertations about: "gamma rays: observations"

Showing result 1 - 5 of 14 swedish dissertations containing the words gamma rays: observations.

2. 1. Gamma-Ray Emission from Galaxy Clusters : DARK MATTER AND COSMIC-RAYS

   Author : Anders Pinzke; Lars Bergström; Olaf Reimer; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Galaxy clusters; gamma-rays; cosmic-rays; dark matter; High energy astrophysics; Högenergiastrofysik; teoretisk fysik; Theoretical Physics;

   Abstract : The quest for the first detection of a galaxy cluster in the high energy gamma-ray regime is ongoing, and even though clusters are observed in several other wave-bands, there is still no firm detection in gamma-rays. To complement the observational efforts we estimate the gamma-ray contributions from both annihilating dark matter and cosmic-ray (CR) proton as well as CR electron induced emission. READ MORE

4. 2. Observations of nearby Galaxy Clusters with the Fermi Large Area Telescope : Towards the first Gamma Rays from Clusters

   Author : Stephan Zimmer; Jan Conrad; Lars Bergström; Torsten Enßlin; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Galaxy Clusters; Fermi-LAT; γ rays; Dark Matter; Cosmic Rays; fysik; Physics;

   Abstract : Galaxy clusters are the most massive bound systems known in the Universe and are believed to have formed through large scale structure formation. They host relativistic cosmic-ray (CR) populations and are gravitationally bound by large amounts of Dark Matter (DM), both providing conditions in which high-energy gamma rays may be produced either via CR interactions with the intracluster medium or through the annihilation or decay of DM particles. READ MORE

5. 3. Seeking the faint extremes : Detection and characterisation of extragalactic soft-spectrum gamma-ray sources and exploring methods to enhance their detection with machine learning in the 50 GeV-50 TeV energy range

   Author : Tomas Bylund; Yvonne Becherini; Gilles Henri; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; GeV gamma-rays; TeV gamma-rays; AGN; blazar; deep learning; observational high-energy astronomy; Astroparticle Physics; Astropartikelfysik;

   Abstract : This thesis deals with an observational study of Blazars, strong gamma-ray sources with Very High Energies (VHE) located far outside our Galaxy. Blazars are a class of galaxies that contain a supermassive black hole that is actively consuming large quantities of matter, a process that results in the liberation of tremendous amounts of energy that then powers the emission of huge bulks of charged particles that get accelerated almost to the speed of light. READ MORE

6. 4. Parametric Model for Astrophysical Proton-Proton Interactions and Applications

   Author : Niklas Karlsson; Per Carlson; Simon Swordy; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; astrophysics; gamma rays; proton-proton interactions; cosmic rays; Astronomy and astrophysics; Astronomi och astrofysik;

   Abstract : Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. READ MORE

7. 5. Search for Gamma-ray Lines from Dark Matter with the Fermi Large Area Telescope

   Author : Tomi Ylinen; Mark Pearce; Jan Conrad; Staffan Carius; James T. Linnemann; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Fermi; Large Area Telescope; gamma-rays; dark matter; spectral lines; beam test; Physics; Fysik; Astroparticle physics; Astropartikelfysik;

   Abstract : Dark matter (DM) constitutes one of the most intriguing but so far unresolved issues in physics. In many extensions of the Standard Model of particle physics, the existence of a stable Weakly Interacting Massive Particle (WIMP) is predicted. The WIMP is an excellent DM particle candidate. READ MORE