Sökning: "Stellar Spectroscopy"

Visar resultat 6 - 10 av 26 uppsatser innehållade orden Stellar Spectroscopy.

  1. 6. Towards a high resolution view of infrared line formation

    Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

    Författare :Martin Schmidt Montelius; [2021]
    Nyckelord :Spectroscopy; Near infrared; K giants; Galactic archeaology; Galactic chemical evolution; Abundances; Milky Way; Physics and Astronomy;

    Sammanfattning : Observing in the infrared has many benefits, such as seeing through the interstellar dust in the galaxy, easier use of adaptive optics, and better flux ratios for direct observations of exoplanets. Before the infrared spectral range can be utilised for highly accurate stellar spectroscopy there is a need for a better understanding of both stellar modelling and the atomic physics that go into forming spectral lines. LÄS MER

  3. 7. Advanced Characterization of Exoplanet Host Stars

    Master-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Khaled Al Moulla; [2020]
    Nyckelord :stars: exoplanet hosts - fundamental parameters - spectroscopy: HARPS - SME; stjärnor: exoplanetvärdar - fundamentala parametrar - spektroskopi: HARPS - SME;

    Sammanfattning : The spectroscopic determination of stellar properties is important for subsequent studies of exoplanet atmospheres. In this thesis, HARPS data for 6 exoplanet-hosting, late-type stars is processed to achieve an average signal-to-noise ratio of ~105. LÄS MER

  4. 8. Archaeologic inspection of the Milky Way using vibrations of a fossil : Seismic, spectroscopic and kinematic characterization of a binary metal-poor Halo star

    Kandidat-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Amanda Byström; [2020]
    Nyckelord :Milky Way; Halo; galactic archaeology; asteroseismology; binary star; CEMP stars; CEMP-r s stars; stellar age; stellar mass; chemical abundance pattern; Gaia-Enceladus; Gaia-Sausage; Sequoia; spectroscopy; metal-poor;

    Sammanfattning : The Milky Way has undergone several mergers with other galaxies during its lifetime. The mergers have been identified via stellar debris in the Halo of the Milky Way. The practice of mapping these mergers is called galactic archaeology. To perform this archaeologic inspection, three stellar features must be mapped: chemistry, kinematics and age. LÄS MER

  5. 9. Accurate Abundances of Giant Stars in the Local disk: A manual analysis of IR APOGEE spectra

    Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation; Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

    Författare :Ivalu Barlach Christensen; [2020]
    Nyckelord :Galactic Chemical Evolution; Astrophysics; Astronomy; IR Spectroscopy; Milky Way; Abundance; Physics and Astronomy;

    Sammanfattning : Purpose: In order to study the Galactic Chemical Evolution, elemental abundances are needed. The purpose of this work is to investigate the chemical evolution of the Milky Way by determining several elemental abundances of giants in the local disk. LÄS MER

  7. 10. Collisional broadening by hydrogenfor stellar spectroscopy : extension towards high-lying states

    Kandidat-uppsats, Uppsala universitet/Teoretisk astrofysik

    Författare :Adam Hultquist; [2019]
    Nyckelord :Astrophysics; Spectral line broadening; ABO; Collisional broadening;

    Sammanfattning : The object of this thesis is to extend the current tables for two useful quantities when calculatingcollisional broadening, the cross-section of interaction and the velocity parameter.These quantities, which have hitherto been tabulated for lower states, have now been calculatedfor higher lying states and are used in the ABO - model for spectral line broadening. LÄS MER