Sökning: "Abundances"

Visar resultat 1 - 5 av 180 avhandlingar innehållade ordet Abundances.

  1. 1. Molecules and Dust around AGB stars : Mass-loss rates and molecular abundances

    Författare :Sofia Ramstedt; Hans Olofsson; Fredrik Schöier; José Cernicharo; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AGB stars; mass-loss; circumstellar abundances; Formation and development of stars; Stjärnors bildning och utveckling; Astronomy; astronomi;

    Sammanfattning : All stars with a stellar mass of about 0.8–8 MSun will end their lives as asymptotic giant branch (AGB) stars. Through their extensive mass loss the AGB stars constitutes an important source of nuclear processed material. LÄS MER

  3. 2. 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

  4. 3. Asymptotic Giant Branch stars viewed up-close and far-off : The physics, chemistry, and evolution of their circumstellar envelopes

    Författare :Matthias Maercker; Hans Olofsson; Fredrik L. Schöier; Laurentius B. F. M. Waters; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AGB stars; evolution; mass-loss; abundances; Astronomy; Astronomi; Astronomy; astronomi;

    Sammanfattning : The asymptotic giant branch (AGB) is the last stage of stellar evolution for stars with masses between 0.8-8 M(sun). This phase is characterised by an intense mass loss, which builds up a circumstellar envelope of dust and gas(CSE). It is through this process that the AGB stars contribute to the chemical evolution of galaxies. LÄS MER

  5. 4. Modelling of molecular clouds

    Författare :Per Bergman; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular radio lines; circumstellar matter; interstellar medium; circumstellar radio lines; H 11 regions; abundances; interstellar matter; galaxies; interstellar radio lines;

    Sammanfattning : .... LÄS MER

  7. 5. Interstellar molecules in the Magellanic clouds

    Författare :Arto Heikkilä; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; abundances; interstellar medium: molecules; galaxies: interstellar medium; magellanic clouds; abundances;

    Sammanfattning : .... LÄS MER