Sökning: "GALAXIES"

Visar resultat 1 - 5 av 146 avhandlingar innehållade ordet GALAXIES.

  1. 1. 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

  3. 2. Neutral gas properties of high-redshift analog galaxies : 21cm observations of Lyα and LyC-emitting galaxies

    Författare :Alexandra Le Reste; Matthew J. Hayes; John Cannon; Rychard Bouwens; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxies; Lyman alpha; Lyman Continuum; 21cm line; Interacting galaxies; Epoch of Reionization; Astronomy; astronomi;

    Sammanfattning : Neutral hydrogen (HI) is the most abundant baryonic element and a crucial component of galaxies. In the early universe, the interaction between neutral gas and the light produced by galaxies is thought to have given rise to cosmological reionization. LÄS MER

  4. 3. Multi frequency interferometer studies of active and starburst galaxies

    Författare :Evert Olsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxies: active; galaxies: ISM; galaxies: starburst; galaxies: evolution;

    Sammanfattning : We report the results of a multi-frequency study of three interactinggalaxies: NGC 5218, NGC 1614 and NGC 4194 (the Medusa merger). These sourcesbelong to different classes of active and starburst galaxies. LÄS MER

  5. 4. Radio Studies of Circumnuclear Gas in Active Galaxies

    Författare :Ylva Pihlström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; techniques: interferometry; galaxies: starbust; galaxies: active; galaxies: nuclei; radio lines: galaxies; techniques: high angular resolution;

    Sammanfattning : In this thesis we have used radio interferometry in order to perform high resolution spectral line studies of circumnuclear gas in AGN and starburst galaxies. Amongst the studied objects is the Seyfert 2 NGC5793, for which we find the high opacity HI absorption to be consistent with a 50-100 pc radius atomic disk aligned with the host galaxy disk. LÄS MER

  7. 5. Dissipative formation of galaxies in hierarchical cosmology

    Författare :John Hultman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; merical methods; hydrodynamics; galaxies: formation; galaxies: elliptical; galaxies: structure; star formation; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : A description and detailed tests of a numerical code for simulations of galaxy formation is presented. The dynamics is followed with fully adaptive and Lagrangian Smooth Particle Hydrodynamics (SPH) combined with a gravitational tree method. The severe numerical problem of sub-resolution clustering is solved by merging of gas particles. LÄS MER