Sökning: "Galactic structure"

Visar resultat 11 - 15 av 22 avhandlingar innehållade orden Galactic structure.

  1. 11. Cosmic tests of massive gravity

    Författare :Jonas Enander; Edvard Mörtsell; Stefan Hofmann; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Modified gravity; massive gravity; cosmology; dark energy; dark matter; fysik; Physics;

    Sammanfattning : Massive gravity is an extension of general relativity where the graviton, which mediates gravitational interactions, has a non-vanishing mass. The first steps towards formulating a theory of massive gravity were made by Fierz and Pauli in 1939, but it took another 70 years until a consistent theory of massive gravity was written down. LÄS MER

  3. 12. Cosmological Dark Matter and the Isotropic Gamma-Ray Background : Measurements and Upper Limits

    Författare :Alexander Sellerholm; Jan Conrad; Karl Mannheim; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dark matter theory; dark matter simulations; dark matter experiments; isotropic gamma-ray background; Fermi gamma-ray space telescope; Astroparticle physics; Astropartikelfysik; teoretisk fysik; Theoretical Physics;

    Sammanfattning : This thesis addresses the isotropic diffuse gamma-ray background, as measured by the Fermi gamma ray space telescope, and its implications for indirect detection of dark matter. We describe the measurement of the isotropic background, including also an alternative analysis method besides the one published by the Fermi-LAT collaboration. LÄS MER

  4. 13. Bird's eye view of star formation in the local Milky Way - How perspective changes with scale, time and viewing angle

    Författare :Andri Spilker; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; interstellar medium; star formation;

    Sammanfattning : A crucial aspect in interpreting the scaling relations relevant for star formation—the Kennicutt-Schmidt relation and the Larson relations—is how those relations depend on size-scale. This is especially so when comparing relations derived from unresolved, extragalactic data to those derived from resolved, Galactic data. LÄS MER

  5. 14. Bird's-eye view of molecular clouds in the Milky Way

    Författare :Andri Spilker; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Interstellar medium; column density statistics; star formation;

    Sammanfattning : A crucial aspect in interpreting the scaling relations relevant for star formation - the Kennicutt-Schmidt relation and the Larson relations - is how those relations depend on size-scale. This is especially so when comparing relations derived from unresolved, extragalactic data to those derived from resolved, Galactic data. LÄS MER

  7. 15. Deep photometry of galaxies : to see or not to see /Magnus Näslund

    Författare :Magnus Näslund; Nils Bergvall; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomi; Astronomy; astronomi;

    Sammanfattning : The edge-on spiral galaxy NGC 4565 and the distant galaxy cluster MS2255.7+2039 have been studied at optical wavelengths with deep photometry using the 2.56 m Nordic Optical Telescope on La Palma.By careful data reductions we traced the surface brightness of NGC 4565 to faint levels. LÄS MER