Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 12 of 12 for “"metal-poor stars"”.
-
Chemical and kinematic properties of bright metal poor stars
… I analyze the high-resolution spectra of 20 stars, chosen for their low metallicity [Fe/H] </~ -2.5 and proximity to the sun. Using these spectra I model the atmospheres of these stars by determing stellar parameters {Teff, log(g), [mu], [Fe/H]} and obtain also their chemical abundances for …
-
Maišymosi procesai nemetalingose žvaigždėse /
Mixing Processes in Metal-poor Stars.
-
Hobby-Eberly Telescope Chemical Abundances of Stars in the Halo (CASH) project : spectroscopic analyses of the first ~80 stars
The Hobby-Eberly Telescope Chemical Abundances of Stars in the Halo (CASH) project aims to characterize the nature of the early universe through the study of metal-poor stars in the stellar halo of the galaxy. Once completed, this will be the largest set of abundances determined for metal-poor …
-
Mapping the Ancient Milky Way and its Relic Dwarf Galaxies
… billion years after the Big Bang, the first stars and galaxies began transforming the dark, primitive universe into the rich, complex one that we observe today. These primitive objects thus govern crucial, foundational rungs in our understanding of how the universe came to be. However, little …
-
A Kinematic and Abundance Survey of the Galactic Pole Regions
DDO observations of 1076 G and K stars at the north and south galactic poles are combined with published photometry to give a new abundance gradient perpendicular to the galactic plane to z-distances greater than 5 kpc. Additional DDO photometry of bright field stars has been used to calibrate the …
-
Chemical and kinematical evolution in nearby dwarf spheroidal galaxies
… stand in contradiction to the properties of stars in the Galactic halo. Further, yet unsolved, puzzles include the missing satellite problem, the influence of feedback and reionization, and the nature of dark matter. How then do the dSphs form, to what extent do they contribute to the …
-
Kinematics and stellar populations of the galactic bulge.
… radial and/or rotation velocities and obtain metallicities for the stellar population of the Galactic bulge, several hundred spectra of giants have been obtained. These include three bulge fields at projected distances from the Galactic center of 1.5, 1.7 and 1.7 kpc, and 33 globular and open …
-
Kinematic and Abundance Gradients in the Galactic Disk
… and DDO and BV photometry of 364 G and K stars in the galactic center and anticenter directions have been obtained for the purpose of investigating the gradients of abundance and velocity dispersion in the galactic disk. The abundance gradient found for these stars is d (Fe/H) /dR = …
-
Schwerebeschleunigungen Kühler Sterne
… singly-ionized iron in the atmospheres of cool stars in presented. It accounts for departures from local thermodynamic equilibrium –so-called non-LTE effects –an d serves the derivation of spectroscopic stellar gravities “g” via the ionization equilibrium constraint. The respective influence of …
-
New insights into primeval galaxies in the era of JWST
… to measure the temperature, surface gravity and metallicity of observed stars. I also show that these spectra can be used to identify candidate carbon-enriched metal-poor stars for follow-up high-resolution observations.
-
Resolved stellar populations: watching galaxy evolution in real time
… the galaxy and the evolution of the mass and metallicity distributions. The system that has been studied in this project is the nearby galaxy M33, located in the Local Group. The photometric data was taken in the Canada-France-Hawaii Telescope with the MegaPrime/MegaCam wide-field mosaic …