Search for dissertations about: "Astronomy and astrophysics"

Showing result 1 - 5 of 299 swedish dissertations containing the words Astronomy and astrophysics.

  1. 1. From irrotational flows to turbulent dynamos

    Author : Fabio Del Sordo; Axel Brandenburg; Mordecai-Mark Mac Low; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; astrophysics; magnetic fields; insterstellar medium; MHD; dynamo; turbulence; instability; Astronomy; astronomi;

    Abstract : Many of the celestial bodies we know are found to be magnetized:the Earth, many of the planets so far discovered, the Sun and other stars,the interstellar space, the Milky Way and other galaxies.The reason for that is still to be fully understood, and this work is meant to be a step in that direction. READ MORE

  2. 2. Optical Turbulence Characterization for Ground-Based Astronomy

    Author : Susanna Hagelin; Anna Rutgersson; Elena Masciadri; Valentina Zitelli; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; site testing; atmospheric effects; turbulence; optical turbulence; applied meteorology; mesoscale models; Meteorology; Meteorologi; Astronomy and astrophysics; Astronomi och astrofysik; Meteorologi; Meteorology;

    Abstract : The optical turbulence, which creates perturbations of the wavefronts coming from the stars, is caused by small-scale fluctuations in the index of refraction of the atmosphere and is a problem for astronomers because it limits the maximum resolution of the ground-based telescopes. One way of identifying the best sites to build astronomical observatories, where the influence of the optical turbulence is as small as possible, is to use the standard meteorological parameters to get a first idea of the potential of a site. READ MORE

  3. 3. Thermophysical Modelling and Mechanical Stability of Cometary Nuclei

    Author : Björn Davidsson; Dina Prialnik; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Comets; Tidal physics; Light scattering; Radiative transfer; Thermophysics; Gas kinetics; Non-gravitational forces; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Abstract : Comets are the most primordial and least evolved bodies in the Solar System. As such, they are unique sources of information regarding the early history of the Solar System. However, little is known about cometary nuclei since they are very difficult to observe due to the obscuring coma. READ MORE

  4. 4. Quasar host galaxies at intermediate and high redshifts

    Author : Eva Örndahl; Bengt Gustafsson; Jari Kotilainen; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Active galaxies; Quasars; Host galaxies; Imaging; Photometry; Magnitudes; Colours; Morphology; Statistical methods; High-redshift; Infrared; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Abstract : Quasars form one of the most energetic phenomena in the universe, and can be traced out to very large redshifts. By studying the galaxies which host the active nuclei, important insights can be gained into the processes that trigger and maintain the quasar powerhouse. READ MORE

  5. 5. Laboratory and stellar spectroscopy of the complex ions Fe+, Mo+, Th+ and U+

    Author : Hampus Nilsson; Astronomi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; molybdenum; iron; thorium; uranium.; Atomic and molecular physics; Atom- och molekylärfysik; Astronomy; space research; cosmic chemistry; Astronomi; rymdvetenskap; kosmisk kemi; Condensed matter:electronic structure; electrical; spektroskopi; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; magnetic resonance; magnetic and optical properties; supraconductors; astrophysics; radiative lifetimes; oscillator strengths; term analysis; Fourier transform spectroscopy; branching fractions; Fysicumarkivet A:2002:Nilsson;

    Abstract : The new generation of high resolution astronomical instruments such as the Hubble Space Telescope (HST) or the Very Large Telescope (VLT) has renewed the demand for accurate atomic parameters like wavelengths, oscillator strengths and line profiles accompanied by reliable uncertainty estimates. Fourier transform spectroscopy has proven to be a powerful tool when measuring these parameters. READ MORE