Search for dissertations about: "circumstellar dust"

Showing result 1 - 5 of 25 swedish dissertations containing the words circumstellar dust.

  2. 1. Circumstellar Debris Disks : Observational Studies of Cold Dust and Gas Emission in Planetary Nurseries

    Author : Ricky Nilsson; Alexis Brandeker; Mark Wyatt; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; circumstellar disks; debris disks; Kuiper belts; planet formation; submillimeter imaging; photometry; coronagraphy; integral-field spectroscopy; Astronomy; astronomi;

    Abstract : Planetary systems form in disks of gas and dust surrounding newborn stars. The young circumstellar environment is characterized by frequent collisions between rocky bodies, leading to a continuous production of small dust grains. READ MORE

  4. 2. Sources of Dust Extinction in Type Ia Supernovae : Measurements and constraints from X-rays to the Infrared

    Author : Joel Johansson; Edvard Mörtsell; Ariel Goobar; Rahman Amanullah; Bruno Leibundgut; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; supernovae; interstellar dust; circumstellar dust; cosmology; fysik; Physics;

    Abstract : The use of Type Ia supernovae (SNe Ia) as distance indicators is essential for studying the expansion history of the Universe and for exploring the nature of dark energy. However, a lack of understanding of the progenitor systems and the empirically derived colour-brightness corrections represent severe limitations for SNe Ia as cosmological probes. READ MORE

  5. 3. Dynamical atmospheres and winds of M-type AGB stars

    Author : Sara Bladh; Susanne Höfner; Kjell Eriksson; Patricia Whitelock; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Late-type stars; AGB stars; stellar winds; atmospheres; mass-loss; outflows; circumstellar matter; dust; hydroynamics; radiative transfer; Astronomy with specialization in Astrophysics; Astronomi med intiktning mot astrofysik;

    Abstract : Mass loss, in the form of slow stellar winds, is a decisive factor for the evolution of cool luminous giants, eventually turning them into white dwarfs. These dense outflows are also a key factor in the enrichment of the interstellar medium with newly produced elements from the interior of these stars. READ MORE

  6. 4. 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

  7. 5. 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