Sökning: "galaxies: formation"

Visar resultat 1 - 5 av 71 avhandlingar innehållade orden galaxies: formation.

  1. 1. 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

  3. 2. 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

  4. 3. 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

  5. 4. Water and hydroxyl in luminous infrared galaxies: Spectroscopic observations and modelling

    Författare :Niklas Falstad; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ISM: molecules; Galaxies: individual: Zw 049.057; Line: formation; Galaxies: ISM; Submillimeter: galaxies; Infrared: galaxies;

    Sammanfattning : Many luminous infrared galaxies (LIRGs) contain compact obscured nuclei (CONs) where luminosities in excess of 10^9 Lsun emerge from inside dusty regions smaller than 100 pc in diameter. Due to the obscuring material in these regions, the nature of the nuclear power source cannot be determined using direct observations in the optical or IR. LÄS MER

  7. 5. 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