Sökning: "nucleosynthesis"

Visar resultat 16 - 20 av 22 avhandlingar innehållade ordet nucleosynthesis.

1. 16. Studies of Interstellar Molecular Gas in the Magellanic Clouds

   Författare :Arto Heikkilä; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; abundances-Galaxies; evolution; molecules-Galaxies; Magellanic Clouds-Interstellar medium; molecules-Galaxies; interstellar medium-Galaxies;

   Sammanfattning : Results of observational studies of interstellar molecular gas clouds in the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), two nearby metal-poor and dust-poor dwarf galaxies, are presented. Spectral line radiation emitted by interstellar molecules has been used to probe the physical state and the chemical composition of individual molecular clouds. LÄS MER

3. 17. 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. 18. On the Chemical Composition of Metal-Poor Stars : Impact of Stellar Granulation and Departures from Local Thermodynamic Equilibrium on the Formation of Spectral Lines

   Författare :Remo Collet; Bengt Gustafsson; Martin Asplund; Roger Cayrel; Uppsala universitet; []
   Nyckelord :Astronomy; late-type stars; stellar abundances; stellar atmospheres; spectral line formation; convection; hydrodynamics; Galactic chemical evolution; Astronomi;

   Sammanfattning : The information about the chemical compositions of stars is encoded in their spectra. Accurate determinations of these compositions are crucial for our understanding of stellar nucleosynthesis and Galactic chemical evolution. LÄS MER

5. 19. Studying neutron-induced fission at IGISOL-4 : From neutron source to yield measurements and model comparisons

   Författare :Andrea Mattera; Stephan Pomp; Mattias Lantz; Andreas Solders; Jonathan Wilson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Fission yields represent the probability of producing a certain nuclide in a fission event, and are important observables for fission research. For applications, accurate knowledge of the yields is fundamental at all stages of the fuel cycle of nuclear reactors, e.g., for reactivity calculations, or to estimate (spent) fuel inventory. LÄS MER

7. 20. Non-Local Thermodynamic Equilibrium Spectral Modelling of Kilonovae

   Författare :Quentin Pognan; Anders Jerkstrand; Kyohei Kawaguchi; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Transients: Neutron Star Mergers; Radiative Transfer; Astronomy; astronomi;

   Sammanfattning : The astrophysical origin of rapid neutron capture (r-process) elements has long remained a puzzle and been the object of scientific debate. Neutron star (NS) mergers have historically been suggested as an ideal site for the creation of these elements, and were propelled into focus following the detection of the first binary neutron star (BNS) merger in 2017. LÄS MER