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Showing result 1 - 5 of 76 swedish dissertations matching the above criteria.

  2. 1. Mass Loss of Evolved Stars : Improving Mass-Loss Rates and Distances

    Author : Miora Andriantsaralaza; Paul Barklem; Elvire De Beck; Susanne Höfner; Jacco van Loon; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; AGB stars; Mass loss; Distance; Circumstellar matter; Radio interferometry; Stellar evolution; Fysik med inriktning mot astrofysik; Physics with specialization in Astrophysics;

    Abstract : In the final stages of their lives, low to intermediate-mass stars enter the Asymptotic Giant Branch (AGB) phase, where they experience significant mass loss through dusty stellar winds. This mass loss is pivotal, not only for the chemical enrichment of the interstellar medium, setting the stage for new stars and planets to form, but also in dictating the evolution and the ultimate fate of the stars themselves. READ MORE

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

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

    Abstract : 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. READ MORE

  5. 3. Stellar Winds of Cool Giants : Investigating the Mass-Loss Mechanism of AGB Stars

    Author : Sofie Liljegren; Susanne Höfner; Kjell Eriksson; Bernd Freytag; Hans Olofsson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; late-type stars; AGB stars; stellar winds; stellar atmospheres; dust; stellar pulsation; hydrodynamics; radiative transfer;

    Abstract : Asymptotic giant branch (AGB) stars are luminous cool giants of low to intermediate mass that are strongly pulsating and non-spherical, with heavy mass loss through a stellar wind. The mass loss makes these stars important for galactic chemistry, as the wind enriches the interstellar medium with new elements and dust, and it determines the final fate of these stars. READ MORE

  6. 4. On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study

    Author : Lars Mattsson; Susanne Höfner; Nils Bergvall; Kjell Olofsson; Martin Groenewegen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; AGB stars; carbon stars; mass loss; stellar winds; circumstellar matter; cosmic dust; stellar evolution; nucleosynthesis; galactic chemical evolution; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi; Fysik; Physics;

    Abstract : Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. READ MORE

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

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

    Abstract : 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. READ MORE