Search for dissertations about: "gamma rays"

Showing result 1 - 5 of 65 swedish dissertations containing the words gamma rays.

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

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

    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

  2. 2. 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 : NATURAL SCIENCES; NATURVETENSKAP; 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

  3. 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 : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Galaxy Clusters; Fermi-LAT; γ rays; Dark Matter; Cosmic Rays; Physics; fysik;

    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

  4. 4. Multi-messenger emission from gamma-ray bursts

    Author : Filip Samuelsson; Felix Ryde; Peter Mészáros; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; astrophysics; gamma-ray bursts; cosmic rays; Atomic; Subatomic and Astrophysics; Atomär fysik; subatomär fysik och astrofysik;

    Abstract : Multi-messenger astronomy is a very hot topic in the astrophysical community. A messenger is something that carries information. Different astrophysical messenger types are photons, cosmic rays, neutrinos, and gravitational waves. They all carry unique and complementary information to one another. READ MORE

  5. 5. Parametric Model for Astrophysical Proton-Proton Interactions and Applications

    Author : Niklas Karlsson; Per Carlson; Simon Swordy; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; 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