Sökning: "Galaxy: evolution"

Visar resultat 6 - 10 av 74 avhandlingar innehållade orden Galaxy: evolution.

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

    Författare :Chiara Battistini; Astronomi - Genomgår omorganisation; []
    Nyckelord :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

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

    Författare :Iryna Kushniruk; Astronomi - Genomgår omorganisation; []
    Nyckelord :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

  4. 8. Clues to galaxy evolution from spectroscopic observations of Galactic centre stars

    Författare :Brian Thorsbro; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical abundances; Late-type stars; Star clusters; Galactic center; Galaxy chemical evolution; Chemical enrichment;

    Sammanfattning : In this work we present results from spectroscopic observations of Galactic centre stars. High resolution stellar spectroscopy can be used to determine accurate stellar metallicities and abundances. Observing stars in the Galactic centre is challenging due to extreme extinction. LÄS MER

  5. 9. On the origin and evolution of blue compact galaxies

    Författare :Göran A. Östlin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galaxies - compact; formation; evolution; starburst; interactions; dwarf; photometry; kinematics and dynamics; low surface brightness galaxies; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

    Sammanfattning : This thesis is focused on the origin and evolution of blue compact galaxies (BCGs). BCGs are low mass galaxies characterised by blue colours, low chemical abundances and high star formation rates. The gas consumtion time scale is considerable shorter than the age of the universe and thus the high star formation rate must be transient. LÄS MER

  7. 10. Gas and dust in early galaxy evolution

    Författare :Jean Baptiste Jolly; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxies: evolution -- Galaxies: high-redshift -- methods: stacking -- methods: data analysis -- techniques: interferometric;

    Sammanfattning : In order to study the content of distant galaxies without focusing solely on the brightest objects -- the tip of the iceberg -- I developed a tool:  LineStacker. As its name indicates this tool was designed to perform spectral stacking analyses. LÄS MER