Sökning: "Galactic composition"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Galactic composition.

  1. 1. Dark Matter in the Solar System, Galaxy, and Beyond

    Författare :Axel Widmark; Jens Jasche; Malcolm Fairbairn; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dark matter: phenomenology; dark matter: indirect detection; dark matter: particle nature; Galactic dynamics; Galactic composition; Theoretical Physics; teoretisk fysik;

    Sammanfattning : There is evidence that dark matter constitutes a majority of the Universe's matter content. Yet, we are ignorant about its nature. Understanding dark matter requires new physics, possibly in the form of a new species of fundamental particles. LÄS MER

  3. 2. On the Chemical Composition of Metal-Poor Stars : Impact of Stellar Granulation and Departures from Local Thermodynamic Equilibrium on the Formation of Spectral Lines

    Författare :Remo Collet; Bengt Gustafsson; Martin Asplund; Roger Cayrel; Uppsala universitet; []
    Nyckelord :Astronomy; late-type stars; stellar abundances; stellar atmospheres; spectral line formation; convection; hydrodynamics; Galactic chemical evolution; Astronomi;

    Sammanfattning : The information about the chemical compositions of stars is encoded in their spectra. Accurate determinations of these compositions are crucial for our understanding of stellar nucleosynthesis and Galactic chemical evolution. LÄS MER

  4. 3. Dwarf and Subgiant Stars as Probes of Galactic Chemical and Dynamical Evolution

    Författare :Patrik Thorén; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Abundances; atomic data; Galactic evolution; late-type stars; main sequence stars; subgiants; Pop II; Pop I; stellar evolution; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

    Sammanfattning : Stellar chemical abundances provide astronomers with vital information about the production of chemical elements. Some stars preserve the composition of the environment in which they were born on their surfaces. LÄS MER

  5. 4. Galactic archaeology with metal-poor stars

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

    Sammanfattning : 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. LÄS MER

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

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

    Sammanfattning : 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. LÄS MER