Sökning: "Galaxy Clusters"

Visar resultat 21 - 25 av 34 avhandlingar innehållade orden Galaxy Clusters.

  1. 21. Dust in the early universe

    Författare :Erik Elfgren; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Fysik;

    Sammanfattning : This Licentiate thesis treats the impact of early dust on the Cosmic Microwave Background (CMB). The dust that is studied comes from the first generation of stars, which were hot and short-lived, ending their lives as giant supernovæ. LÄS MER

  3. 22. Supernovae seen through gravitational telescopes

    Författare :Tanja Petrushevska; Rahman Amanullah; Ariel Goobar; Saurabh Jha; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supernovae; strong gravitational lensing; star formation history; supernova rates; supernovor Gravitationslins; fysik; Physics;

    Sammanfattning : Galaxies, and clusters of galaxies, can act as gravitational lenses and magnify the light of objects behind them. The effect enables observations of very distant supernovae, that otherwise would be too faint to be detected by existing telescopes, and allows studies of the frequency and properties of these rare phenomena when the universe was young. LÄS MER

  4. 23. 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

  5. 24. Molecular gas and ionizing radiation in star-forming galaxies

    Författare :Johannes Puschnig; Matthew Hayes; Göran Östlin; Amélie Saintonge; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrophysics; galaxies; star formation; starburst; interstellar medium; Lyman continuum; Lyman alpha; reionization; gravitational instability; molecular gas; clump formation; Astronomy; astronomi;

    Sammanfattning : In cosmic history, some of the major changes such as reionization were driven by baryons (i.e. the stars and gas in galaxies), despite the fact that they contribute only few percent to the total mass-energy budget in the Universe. LÄS MER

  7. 25. Interacting Giants and Compact Stars

    Författare :Alexey Bobrick; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars Binaries: General; stars : neutron; stars : subdwarfs; stars : supergiants; hydrodynamics; nuclear reactions; nucleosynthesis; abundances; stars Binaries: General; stars : neutron; stars : subdwarfs; stars : supergiants; hydrodynamics; nuclear reactions; nucleosynthesis; abundances; Fysicumarkivet A:2021:Bobrick;

    Sammanfattning : This thesis is based on four papers dealing with various aspects of interactions in binary stars. Interactions between stars occur at nearly all stages of their evolution and can take many forms. LÄS MER