Search for dissertations about: "galactic evolution"

Showing result 16 - 20 of 48 swedish dissertations containing the words galactic evolution.

  2. 16. On the Abundances of Li, Be and O in Metal-Poor Stars in the Galaxy

    Author : Ana Elia García Pérez; Martin Asplund; Bengt Gustafsson; Francesca Primas; Beatriz Barbuy; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galactic evolution; stellar abundances; stellar atmospheres; spectral line formation; stellar mixing; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

    Abstract : Stellar atmospheres constitute excellent environments to study the chemical evolution of our Galaxy. The chemical composition of these atmospheres reflects the composition of the gas from where these stars were born. READ MORE

  4. 17. The environment of active galactic nuclei : excess counts and the nature of their host clusters

    Author : Margrethe Wold; Christopher D. Impey; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

    Abstract : This thesis presents observations of the galaxy environment of active galactic nuclei on galaxy cluster scales. In the first part, we quantify the galaxy environment of a sample of 40 quasars, consisting of equal fractions of radio-loud and radio-quiet sources. The sample covers a narrow range in redshift, 0.5 < z < 0. READ MORE

  5. 18. Galactic archaeology with metal-poor stars

    Author : Thomas Nordlander; Andreas J. Korn; Karin Lind; Ulrike Heiter; David L. Lambert; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: abundances; radiative transfer; stars: Population II; stars: Population III;

    Abstract : The chemical fingerprints of old, metal-poor stars can be used to unravel the events of the newborn Universe and help us understand the properties of the first stars and star clusters. The study of nearby stars to infer properties in the distant past is often referred to as Galactic archaeology. READ MORE

  6. 19. Variability and evolution of the broad-line region in active galactic nuclei

    Author : Ignaz Wanders; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : .... READ MORE

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

    Author : Chiara Battistini; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Stars: abundances; Stars: solar-type; Galaxy: disk; Galaxy: evolution; Galaxy: solar neighbourhood;

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