Sökning: "stellar parameters"

Visar resultat 26 - 30 av 58 uppsatser innehållade orden stellar parameters.

  1. 26. 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

  3. 27. Analysis of stellar spectra with machine learning

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

    Författare :Alvaro Segovia Otero; [2020]
    Nyckelord :Galactic Archaeology; machine learning; chemical abundances; FGK stars; Physics and Astronomy;

    Sammanfattning : Researchers in the field of Galactic Archaeology have entered the era of industrial revolution. Upcoming surveys are planning on observing tens of millions of stars and high precision and accuracy must be ensured when deriving their stellar parameters and elemental abundances. LÄS MER

  4. 28. Chaos in Stellar Dynamics - Outcomes of Binary-Single interactions in Globular Clusters

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

    Författare :Lucas Hellström; [2020]
    Nyckelord :Stellar Dynamics; Binary-Single interactions; Dynamical encounters; Additional processes; Physics and Astronomy;

    Sammanfattning : Gravitational encounters between a single star and a binary system can frequently occur in the cores of dense stellar systems like globular clusters. These three-body scattering encounters can lead to a variety of outcomes since the energy of the binary components can be exchanged with the interacting single star. LÄS MER

  5. 29. Identifying Gravitationally Lensed QSO Candidates with eROSITA

    Master-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Róisín O'Rourke Brogan; [2020]
    Nyckelord :active galactic nuclei; agn; erosita; gaia; gravitational lensing; quasi-stellar objects; strong lensing; multiple images;

    Sammanfattning : As of June 2020, the first all-sky X-ray survey with the eROSITA instrument aboard the spacecraft Spektr-RG has been completed. A high percentage of the 1.1 million objects included in the survey are expected to be active galactic nuclei (AGN). LÄS MER

  7. 30. 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