Search for dissertations about: "submillimeter"

Showing result 21 - 25 of 41 swedish dissertations containing the word submillimeter.

  2. 21. Circumstellar dust emission from nearby Solar-type stars

    Author : Joachim Wiegert; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Stars: binaries - Stars: circumstellar matter - Infrared: stars - Infrared: planetary systems - Submillimeter: stars;

    Abstract : Far-infrared excess above the photosphere of a star indicates the presence of a circumstellar dust disc which is a sign-post for extrasolar planets, and was first detected in the mid 1980s. Dust discs are intricately connected to planets and planetesimals, give insights in the dynamics and evolution of the system, and are also useful for future exoplanet-observations. READ MORE

  4. 22. Extrasolar Kuiper and asteroid belts Modelling far-infrared dust emission

    Author : Joachim Wiegert; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Stars: binaries - Stars: circumstellar matter - Infrared: stars - Infrared: planetary systems - Submillimeter: stars;

    Abstract : The first detections of circumstellar dust emission were announced in the mid 1980s. Direct observations of the edge-on disc of beta Pictoris provided evidence that the dust was part of possible planetary systems. About a decade later, in 1995, the first confirmed extrasolar planet around a main sequence star (51 Pegasi b) was announced. READ MORE

  5. 23. 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. 24. 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. 25. Detection and 3-D positioning of small defects using digital radiography, 3-D point reconstruction, and tracking

    Author : Erik Lindgren; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pore Defects; Radiographic Testing; Nondestructive Evaluation; Laser Welded Titanium; Multiple Hypothesis Tracking; X-ray Testing;

    Abstract : The weight and quality concerned aero industry is constantly trying to decrease the excess material in their components. With decreased weight the fuel consumption can be lowered and the negative environmental effects from aviation decreased. READ MORE