Sökning: "massiva stjärnor"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden massiva stjärnor.

  1. 1. Spectral modeling of nebular-phase supernovae

    Författare :Anders Jerkstrand; Claes Fransson; Luc Dessart; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supernovae; nucleosynthesis; radiative transfer; massive stars; 1987A; IIP; supernovor; nukleosyntes; spektralmodellering; strålningstransport; massiva stjärnor; 1987A; IIP; Astronomy; astronomi;

    Sammanfattning : Massive stars live fast and die young. They shine furiously for a few million years, during which time they synthesize most of the heavy elements in the universe in their cores. They end by blowing themselves up in a powerful explosion known as a supernova (SN). LÄS MER

  2. 2. The cosmic origin of fluorine and sulphur: Infrared spectroscopic studies of red giants

    Författare :Henrik Jönsson; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical evolution; near-infrared and mid-infrared spectroscopy; stellar abundances;

    Sammanfattning : Disregarding the small primordial traces of the lightest elements, all metals have been formed in stellar processes, which means that the relative amount of metals in the Universe increases for every stellar generation. This build-up of elements is called chemical evolution and might be used both to constrain stellar models as well as understanding the formation and evolution of stellar populations. LÄS MER

  3. 3. The origin and chemical evolution of iron-peak and neutron-capture elements in the Milky Way disk

    Författare :Chiara Battistini; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stars: abundances; Stars: solar-type; Galaxy: disk; Galaxy: evolution; Galaxy: solar neighbourhood;

    Sammanfattning : All the elements heavier than Li are created during stellar evolution. Even if our knowledge of this process is good, many questions still remain. LÄS MER

  4. 4. Spectral Analysis of Neutron Capture Elements in the Laboratory and Stars

    Författare :Martin Lundqvist; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cosmic chemistry; Astronomy; space research; Atom- och molekylärfysik; Atomic and molecular physics; Astronomi; Sm; Hf; Os; Ir; Neutron capture processes; rymdvetenskap; kosmisk kemi; cool stars; Spectroscopy; atomic data;

    Sammanfattning : The pedigree of the elements heavier than iron is a vital question in the history and evolution of our galaxy. The elements up to and including those of the iron group are produced mainly through fusion processes within stars, giving the stars their energy. LÄS MER

  5. 5. Core-collapse Supernovae : Theory vs. Observations

    Författare :Dennis Alp; Josefin Larsson; Sergey Tsygankov; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astrophysics; Supernovae; Fysik; Physics;

    Sammanfattning : A core-collapse supernova (CCSN) is an astronomical explosion that indicates the death of a massive star. The iron core of the star collapses into either a neutron star or a black hole while the rest of the material is expelled at high velocities. LÄS MER