Search for dissertations about: "abundances - ISM"

Showing result 6 - 10 of 11 swedish dissertations containing the words abundances - ISM.

  2. 6. Water in molecular outflows and shocks: Studies with Odin and Herschel

    Author : Per Bjerkeli; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Herbig-Haro objects – ISM:individual objects: HH 54; outflows; VLA 1623 – ISM:jets and outflows – ISM:molecules – ISM:abundances – ISM:supernova remnants – stars:formation – stars:pre-main-sequence – stars:winds;

    Abstract : This thesis describes observations and analyses of water in molecular outflows from young stellar objects. The abundance of this molecule (with respect to molecular hy- drogen) is deduced from observations carried out with primarily the Odin and Herschel telescopes. READ MORE

  4. 7. Interstellar absorption across the electromagnetic spectrum

    Author : Achim Tappe; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; interstellar medium ISM : general; supernova remnants Crab Nebula ; emission lines; — quasars: absorption lines;

    Abstract : We report results of a multi-wavelength study of interstellar absorption in diffuse molecular clouds that lie in the direction of flat-spectrum quasars. Quasars as back-ground sources allow the measurement of Galactic interstellar absorption across the electromagnetic spectrum from mm to X-ray wavelengths. READ MORE

  5. 8. Molecular observations at high and low redshifts with the Odin satellite

    Author : Carina Persson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ISM: abundances -- ISM: molecules -- ISM: individual Orion KL -- ISM: individual S140 -- Radio lines: ISM -- Submillimeter -- Line: profiles -- Line: formation -- Cosmology: early Universe -- Cosmology: observations;

    Abstract : The papers in this thesis have the aim of expanding our knowledge of different processes related to star formation in the early Universe and at present times. A complex chemistry occurs in star forming clouds and by observing molecules, information about the necessary physical and chemical conditions for star formation can be obtained. READ MORE

  6. 9. The death throes of massive stars

    Author : Sofia Wallström; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; submillimeter: ISM -- ISM: supernova remnants -- ISM: individual objects: Cassiopeia A -- circumstellar matter -- stars: AGB and post-AGB -- stars: mass-loss -- stars: individual: IRAS 17163-3907 -- quasars: absorption lines -- quasars: individual: B 0218 357 -- galaxies: ISM -- galaxies: abundances -- ISM: molecules;

    Abstract : Massive evolved stars affect their local surroundings as they go through phases of intense mass-loss and eventually explode as supernovae, adding kinetic energy and freshly synthesised material to the interstellar medium. The circumstellar material ejected by the star affects the shape and evolution of the future supernova remnant, and how the material is incorporated into the interstellar medium. READ MORE

  7. 10. Charting Circumstellar Chemistry of Carbon-rich AGB Stars

    Author : Ramlal Unnikrishnan Nair; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; submillimeter: stars; astrochemistry; stars: mass-loss; circumstellar matter; stars: winds; outflows; Stars: AGB and post-AGB;

    Abstract : Stars of low to intermediate initial masses (0.8 - 8 M⊙) enter the asymptotic giant branch (AGB) phase during their late evolution. READ MORE