Sökning: "NATURVETENSKAP Fysik Astronomi och astrofysik Astropartikelfysik"

Visar resultat 6 - 10 av 19 avhandlingar innehållade orden NATURVETENSKAP Fysik Astronomi och astrofysik Astropartikelfysik.

1. 6. Investigating subphotospheric dissipation in gamma-ray bursts by fitting a physical model

   Författare :Björn Ahlgren; Josefin Larsson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics;

   Sammanfattning : .... LÄS MER

3. 7. Subphotospheric dissipation in gamma-ray bursts observed by the Fermi Gamma-ray Space Telescope

   Författare :Björn Ahlgren; Josefin Larsson; Ross Church; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics;

   Sammanfattning : Gamma-ray bursts (GRBs) are the brightest events in the Universe, for a short time outshining the rest of the Universe combined, as they explode with isotropic equivalent luminosities up to $10^{54}$ erg s$^{-1}$. These events are believed to be connected to supernovae and to binary compact object mergers, such as binary neutron stars or neutron star -- black hole systems. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

5. 9. Measurements of hard X-ray polarization from the Crab and Cygnus X-1

   Författare :Victor Mikhalev; Mark Pearce; Herman Marshall; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics; Fysik; Physics;

   Sammanfattning : Polarimetry provides insights into the emission mechanisms of astrophysical sources by elucidating their magnetic field and geometry. Hard X-rays are produced in \mbox{regions} with strong magnetic fields or strong gravitational effects, which makes them a probe of extreme environments. LÄS MER

7. 10. Lessons learned from time-resolved X-ray spectra of gamma-ray bursts

   Författare :Vlasta Valan; Josefin Larsson; Nederländern Professor Andrew Levan Nederländern Radboud Universiteit Andrew Levan; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

   Sammanfattning : Gamma-ray bursts (GRBs) are among the brightest and most energetic phenomena in the Universe, observed up to great distances. The early X-ray emission ofgamma-ray bursts are usually well described by absorbed power laws. However,in some cases, additional thermal components have been identified. LÄS MER