Search for dissertations about: "rays"

Showing result 1 - 5 of 329 swedish dissertations containing the word rays.

2. 1. Searching for Gamma Rays from Galaxy Clusters with the Fermi Large Area Telescope : Cosmic Rays and Dark Matter

   Author : Stephan Zimmer; Jan Conrad; Christophe Clement; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; galaxy clusters; gamma rays; cosmic rays; dark matter; fermi-lat; likelihood analysis; joint likelihood;

   Abstract : In this licentiate thesis, I report a search for GeV γ rays towards the location of Galaxy clusters. I mainly discuss the results of a search for cosmic-ray (CR) induced γ-ray emission but also briefly elaborate on a related study, searching for Dark Matter (DM)-induced γ-ray emission from Galaxy clusters. READ MORE

4. 2. 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

5. 3. 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

6. 4. Phase space methods for computing creeping rays

   Author : Mohammad Motamed; Olof Runborg; Sverker Holmgren; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Creeping Rays; Phase Space Methods; High Frequency Wave Scattering Problems; Numerical analysis; Numerisk analys;

   Abstract : This thesis concerns the numerical simulation of creeping rays and their contribution to high frequency scattering problems. Creeping rays are a type of diffracted rays which are generated at the shadow line of the scatterer and propagate along geodesic paths on the scatterer surface. READ MORE

7. 5. Soft X-rays and secondary electrons : Velocity measurements on the electron emission produced by soft X-rays and by electron impact

   Author : Erik Rudberg; Stockholms högskola; []
   Keywords : ;

   Abstract : .... READ MORE