Sökning: "stellar parameters"

Visar resultat 11 - 15 av 58 uppsatser innehållade orden stellar parameters.

1. 11. Black Hole Dynamics in Stellar Clusters

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

   Författare :Markus Strickert; [2022]
   Nyckelord :Black Holes; Globular Clusters; Dynamics; Intermediate-mass black holes; Simulations; Physics and Astronomy;

   Sammanfattning : Star clusters can harbour many exotic objects, including black holes (BHs), X-ray binaries and blue straggler stars. In dense stellar environments like globular clusters (GCs), two-body relaxation drives their dynamical evolution, where gravitational interactions between stars strive to equalize their kinetic energy in the cluster. LÄS MER

3. 12. An Infrared Stellar Thermometer: Exploiting IGRINS Spectra

   Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Emelie Sandved; [2022]
   Nyckelord :Effective temperature; K-giants; surface gravity; oxygen abundance; carbon abundance; CO lines; OH lines; line sensitivities; Physics and Astronomy;

   Sammanfattning : Using the infrared (IR) spectral range when measuring stellar spectra is beneficial compared to using the optical range mainly when observing distant stars through the dust dense interstellar regions in the Galactic mid-plane. Methods to determine stellar parameters from IR spectra are, however, not fully developed yet because technological difficulties in creating reliable IR detectors have slowed the advance of such methods. LÄS MER

4. 13. Colliding Galaxies in a (Nut)Shell

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation; Lunds universitet/Fysiska institutionen

   Författare :Jonathan Petersson; [2022]
   Nyckelord :shell galaxies; simulations; starbursts; quenching; mergers; Physics and Astronomy;

   Sammanfattning : Galaxy interactions and mergers are natural recurring events in the current cosmological paradigm, events that often coincide with starbursts and enhanced star formation activity. To understand why that is, one can use idealised (non-cosmological) merger simulations, which provide freedom to recreate specific tidally distorted galaxies, and analysis of the time evolution and underlying physics of the star formation activity at a high spatial resolution. LÄS MER

5. 14. Spectroscopic determination of stellar parameters to constrain atomic diffusion in the old open cluster M67

   Kandidat-uppsats, Uppsala universitet/Institutionen för fysik och astronomi

   Författare :Fabian Lundell; [2022]
   Nyckelord :;

   Sammanfattning : In an attempt to check published results on diffusion effects in M67 a non-LTE analysis is made on 28 high resolution FLAMES-UVES spectra of dwarfs and sub-giants around the turnoff point, where core hydrogen fusion halts. This analysis utilizes the software-suites LOTUS and iSpec to determine stellar parameters from equivalent-width measurements. LÄS MER

7. 15. Spectroscopic model characterisation of hot exoplanet atmospheres

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation; Lunds universitet/Fysiska institutionen

   Författare :Elin Sandvik; [2022]
   Nyckelord :Transit method; Transmission spectroscopy; Exoplanets; Hot Jupiter; Modelling; Physics and Astronomy;

   Sammanfattning : Hot Jupiters are gas giants under intense stellar radiation with short orbital periods of only a few days. Due to their large radii, hot temperatures, and large scale heights, hot Jupiters can be observationally characterised in detail through spectroscopy over an entire orbital phase. LÄS MER