Sökning: "Nils Bergvall"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Nils Bergvall.

  1. 1. On the physics and evolution of interacting galaxies : a study based on spectroscopy, UBV photometry and a survey of southern interacting galaxies

    Författare :Nils Bergvall; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  3. 2. On the Escape of Lyman Radiation from Local Galaxies

    Författare :Elisabet Leitet; Nils Bergvall; Erik Zackrisson; Bengt Gustafsson; Duilia F. De Mello; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxies; starbursts; spiral galaxies; Lyman continuum; Lyman alpha; leakage; cosmic reionization; escape fraction; Astronomy; Astronomi;

    Sammanfattning : Cosmic reionization was most likely initiated by star forming dwarf galaxies. Little is known about the physical mechanisms allowing ionizing Lyman continuum (LyC) photons to escape from galaxies, but to learn more we can study local galaxies in detail. LÄS MER

  4. 3. Star-forming Dwarf Galaxies : Internal motions and evolution

    Författare :Thomas Marquart; Nils Bergvall; Janice Lee; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy; Galaxies; Dynamics; Kinematics; Starburst; Dwarf Galaxies; Blue Compact Galaxies; Star Formation; Galaxy mergers; 3D-Spectroscopy; Spectroscopy; Astronomy; Astronomi;

    Sammanfattning : The study of dwarf galaxies is important in order to better understand the physics of the young universe and how larger galaxies form and evolve. In this work we focus on Blue Compact Galaxies (BCGs) which havemuch enhanced star formation (starbursts), causing blue colours and strong emission line spectra. LÄS MER

  5. 4. On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study

    Författare :Lars Mattsson; Susanne Höfner; Nils Bergvall; Kjell Olofsson; Martin Groenewegen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AGB stars; carbon stars; mass loss; stellar winds; circumstellar matter; cosmic dust; stellar evolution; nucleosynthesis; galactic chemical evolution; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi; Fysik; Physics;

    Sammanfattning : Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. LÄS MER

  7. 5. 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