Sökning: "galaxies: structure"

Visar resultat 1 - 5 av 28 avhandlingar innehållade orden galaxies: structure.

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. 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

4. 3. Molecular Gas in Seyfert Galaxies

   Författare :S.J. Curran; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; star-burst-nuclei-dynamics; galaxies; star-burst-nuclei-kinematics; interstellar medium molecules; Seyfert;

   Sammanfattning : In this report we present the results of a single dish study of the molecular gas properties in Seyfert galaxies. From the observations of the closest lying example, the Circinus galaxy, we find that about half of the molecular gas is distributed in a circumnuclear ring orbiting the central super-massive black hole, believed to be powering this type 2 Seyfert. LÄS MER

5. 4. 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. 5. Dynamics of the interstellar matter in galaxies : isolated barred spiral galaxies : cloud formation processes

   Författare :Kristen Helmuth; John Beckman; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomi; Astronomy; astronomi;

   Sammanfattning : The dynamical components of six isolated barred spiral (SB) galaxies are investigated. No evidence is found supporting the hypothesis of a low amount of dark matter being characteristic of SB galaxies. The presence of companion galaxies is found to correlate with an increased statistical spread in the neutral hydrogen (HI) extent. LÄS MER