Sökning: "Gamma-ray emission"

Visar resultat 1 - 5 av 21 uppsatser innehållade orden Gamma-ray emission.

  1. 1. Fitting a photospheric prompt emission model to GRB data: The Kompaneets RMS approximation (KRA)

    Master-uppsats, KTH/Fysik

    Författare :Oscar Wistemar; [2023]
    Nyckelord :Gamma-Ray Bursts; Astrophysics; Engineering Physics; Gamma-Blixtar; Astrofysik; Teknisk Fysik;

    Sammanfattning : Gamma-ray bursts (GRBs) are some of the most energetic events in the universe. Shocks occurring below the photosphere are likely radiation mediated shocks (RMSs) and are suspected to shape the spectra. Due to computational costs of simulating RMSs, models had not been fitted to data and a faster model was needed. LÄS MER

  3. 2. A study of the gamma-ray emission from the blazar S50716+71 using the Fermi-LAT telescope

    Kandidat-uppsats, Linnéuniversitetet/Institutionen för fysik och elektroteknik (IFE)

    Författare :Fredrik Vislander; [2022]
    Nyckelord :AGN; active galactic nuclei; Fermi-LAT; astrophysics; gamma-rays; synchrotron self-Compton; SSC; S50716 71.;

    Sammanfattning : This thesis sums up a bachelor project in which gamma-ray emission from an extra-galactic source (S50716+71) is studied using data collected by the Fermi Large Area Telescope (LAT). The emission consists of 12,5 years of data (April 2008 to February 2020) in the energy range 100 MeV - 300 GeV. LÄS MER

  4. 3. Prompt emission in Gamma-ray bursts; Photospheric Radiation from Synchrotron-Like spectra

    Kandidat-uppsats, KTH/Fysik

    Författare :Erik Vitols; [2022]
    Nyckelord :Gamma-ray burst; radiation mechanisms: thermal and non-thermal;

    Sammanfattning : Gamma-ray bursts (GRBs) are the most luminous phenomena in the Universe, explosions whoseenergy is generated by supernovae or mergers of dense objects such as neutron stars. The GRBemission is divided into the prompt emission phase characterized by γ-ray radiation and the afterglowof lower energy radiation. LÄS MER

  5. 4. Measuring the [C II]-to-H I connection in high-redshift absorption-selected galaxies

    Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

    Författare :Gaurav Senthil Kumar; [2022]
    Nyckelord :QSO; Quasar; Black Hole; AGN; Active Galactic Nuclei; DLA; Damped Lyman Alpha; C II; [C II]; H I; Sightline; HST; X-shooter; Spectroscopy; Echelle Spectroscope; Hyperfine transition; Hyperfine; Physics and Astronomy;

    Sammanfattning : HI neutral gas is the basic building block of galaxies. It dictates the star formation rate and hence the metal enrichment rates within high redshift galaxies. HI neutral gas cannot be directly observed beyond z ≈ 0. LÄS MER

  7. 5. Constraints on the High-Energy Gamma-Ray Spectrum of Nearby Star-Forming Galaxies

    Kandidat-uppsats, Stockholms universitet/Fysikum

    Författare :Oskar Svenborn; [2021]
    Nyckelord :Gamma-ray emission; High-Energy astrophysics; Star-Forming Galaxies; Star formation; Cosmic rays; Fermi-LAT.;

    Sammanfattning : The nature of high-energy gamma-ray emission from Star-Forming Galaxies is of utmost importance for understanding both the origin of Cosmic Rays and the high-energy processes that shape galaxy formation. Observations from the gamma-ray telescope Fermi-LAT have detected gamma-ray emission from a handful of nearby Star-Forming Galaxies. LÄS MER