Sökning: "Galaxy: evolution"

Visar resultat 1 - 5 av 57 avhandlingar innehållade orden Galaxy: evolution.

  1. 1. Star-forming Dwarf Galaxies : Internal motions and evolution

    Författare :Thomas Marquart; Nils Bergvall; Janice Lee; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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. Stochastic Chemical Evolution : A Study of Scatter in Relative Elemental Abundances in Extremely Metal-poor Stars

    Författare :Torgny Karlsson; Bengt Gustafsson; Mike Edmunds; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Astronomy; nucleosynthesis; chemical evolution; Galactic evolution; supernovae; chemical abundances; Population II stars; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

    Sammanfattning : Chemical evolution addresses the problem of the formation of the chemical elements and their evolution throughout the history of the universe. This thesis discusses in particular the chemical evolution in the young universe and what we may learn from the observations of the oldest stars. LÄS MER

  4. 3. The nature of stars with a common origin: clues from metallicity, elemental abundances, and kinematics

    Författare :Cheng Liu; Astronomi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Stars: abundances; Galaxy: evolution; Galaxy: solar neighbourhood; Galaxy: bulge; Galaxy: globular clusters;

    Sammanfattning : Most of field stars originate from dissolved star clusters. If the gas cloud is well mixed the stars in the cluster are expected to be chemically homogenous. LÄS MER

  5. 4. The origin and chemical evolution of iron-peak and neutron-capture elements in the Milky Way disk

    Författare :Chiara Battistini; Astronomi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Stars: abundances; Stars: solar-type; Galaxy: disk; Galaxy: evolution; Galaxy: solar neighbourhood;

    Sammanfattning : All the elements heavier than Li are created during stellar evolution. Even if our knowledge of this process is good, many questions still remain. LÄS MER

  7. 5. The nature of kinematic structures in the Galactic disc

    Författare :Iryna Kushniruk; Astronomi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Galaxy : evolution; Galaxy: structure; Galaxy : kinematics and dynamics;

    Sammanfattning : The velocity distribution of stars in the Galactic disc is complex and consists of a vast number of kinematic structures, that is, stars that share similar velocity components. The reasons why some stars move together may be different and are related to dynamical processes connected to the Galaxy, both internal as well as external ones, such as resonances with the Galactic bar or the Galactic spiral arm structure, dissolution of open clusters, or merger events with other galaxies. LÄS MER