Search for dissertations about: "photosphere"

Showing result 1 - 5 of 13 swedish dissertations containing the word photosphere.

  2. 1. Photospheric emission in gamma ray bursts : Analysis and interpretation of observations made by the Fermi gamma ray space telescope

    Author : Shabnam Iyyani; Felix Ryde; David Burrows; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; gamma ray bursts; photosphere; radiation mechanism; Theoretical Physics; teoretisk fysik;

    Abstract : The large flashes of radiation that are observed in GRBs are generally believed to arise in a relativistic jetted outflow. This thesis addresses the question of how and where in the jet this radiation is produced. READ MORE

  4. 2. Photospheric emission in gamma-ray bursts

    Author : Christoffer Lundman; Felix Ryde; Stephan Rosswog; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis considers emission from gamma-ray bursts (GRBs), the most powerful explosions known in the Universe. Most GRBs are likely associated with the final stages of stellar evolution, where the core of a massive star collapses, and gives birth to a highly compact object such as a neutron star or black hole. READ MORE

  5. 3. Statistical Investigations ofthe Emission Processes in Gamma-ray Bursts

    Author : Zeynep Acuner; Felix Ryde; Judith Racusin; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; gamma-ray bursts; Atomic; Subatomic and Astrophysics; Atomär fysik; subatomär fysik och astrofysik;

    Abstract : Physical emission mechanisms responsible for gamma-ray bursts (GRBs) remain elusive to this day, 50 years after their discovery. Although there are well studied physical models, their power to explain the observed data is a matter of debate. READ MORE

  6. 4. Photospheric emission from structured, relativistic jets : applications to gamma-ray burst spectra and polarization

    Author : Christoffer Lundman; Felix Ryde; Andrei Beloborodov; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; gamma-ray bursts; photospheric emission; radiative processes; polarization; special relativity;

    Abstract : The radiative mechanism responsible for the prompt gamma-ray burst (GRB) emission remains elusive. For the last decade, optically thin synchrotron emission from shocks internal to the GRB jet appeared to be the most plausible explanation. READ MORE

  7. 5. Physical properties of chromospheric features : Plage, peacock jets, and calibrating it all

    Author : Alexander G. M. Pietrow; Dan Kiselman; Jaime de la Cruz Rodríguez; Malcolm Druett; Gianna Cauzzi; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; plage; jets; imaging; spectropolarimetry; Astronomy; astronomi;

    Abstract : The chromosphere is a complex and dynamic layer of the solar atmosphere, largely dominated by the local magnetic field configuration. It acts as an important interface between the photosphere below it and the hot corona above. However, studying this layer is not straightforward, as it is largely transparent in optical wavelengths. READ MORE