Sökning: "NLTE radiative transfer"

Hittade 4 avhandlingar innehållade orden NLTE radiative transfer.

  1. 1. Galactic archaeology with metal-poor stars

    Författare :Thomas Nordlander; Andreas J. Korn; Karin Lind; Ulrike Heiter; David L. Lambert; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars: abundances; radiative transfer; stars: Population II; stars: Population III;

    Sammanfattning : The chemical fingerprints of old, metal-poor stars can be used to unravel the events of the newborn Universe and help us understand the properties of the first stars and star clusters. The study of nearby stars to infer properties in the distant past is often referred to as Galactic archaeology. LÄS MER

  3. 2. 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

  4. 3. A multiwavelength approach to solar chromospheric heating : New insights from the millimeter continuum

    Författare :João Manuel da Silva Santos; Jaime de le Cruz Rodríguez; Jorrit Leenaarts; Petr Heinzel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; radiative transfer; waves; reconnection; Astronomy; astronomi;

    Sammanfattning : The chromosphere is an intermediate layer of the Sun's atmosphere where radiative equilibrium breaks down. The standard chromospheric diagnostics such as the Mg II h and k and Ca II H and K spectral lines are formed under nonlocal thermodynamic equilibrium (NLTE) and they are only partially sensitive to the local conditions. LÄS MER

  5. 4. An Observational Study of Accretion Processes in T Tauri Stars

    Författare :Henricus Cornelis Stempels; Nikolai Piskunov; Gibor Basri; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Star formation; T Tauri stars; Emission lines; Accretion; NLTE radiative transfer; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi;

    Sammanfattning : This thesis is a detailed observational study of the accretion processes in T Tauri stars (TTS). The interaction between the central star, the circumstellar disk and the magnetic field gives rise to a wide range of features in the spectra of TTS. LÄS MER