Sökning: "stars: Population III"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden stars: Population III.

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. Interacting Giants and Compact Stars

   Författare :Alexey Bobrick; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars Binaries: General; stars : neutron; stars : subdwarfs; stars : supergiants; hydrodynamics; nuclear reactions; nucleosynthesis; abundances; stars Binaries: General; stars : neutron; stars : subdwarfs; stars : supergiants; hydrodynamics; nuclear reactions; nucleosynthesis; abundances; Fysicumarkivet A:2021:Bobrick;

   Sammanfattning : This thesis is based on four papers dealing with various aspects of interactions in binary stars. Interactions between stars occur at nearly all stages of their evolution and can take many forms. LÄS MER

4. 3. Gravitational lensing as a probe of the first stars and galaxies

   Författare :Claes-Erik Rydberg; Erik Zackrisson; Lise Christensen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars: Population III; first stars; Galaxies: high-redshift; Galaxies: Population III; dark ages; reionization; techniques: photometric; Astronomy; astronomi;

   Sammanfattning : This thesis investigates the potential for detection and identification of primordial stars, galaxies, and supernovae at high redshift.Simulations indicate that the first Population III stars should appear in minihalos of mass M = 105-106 Msol at z ≈ 10-30. LÄS MER

5. 4. Stochastic Chemical Evolution : A Study of Scatter in Relative Elemental Abundances in Extremely Metal-poor Stars

   Författare :Torgny Karlsson; Bengt Gustafsson; Mike Edmunds; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; nucleosynthesis; chemical evolution; Galactic evolution; supernovae; chemical abundances; Population II stars; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

   Sammanfattning : Chemical evolution addresses the problem of the formation of the chemical elements and their evolution throughout the history of the universe. This thesis discusses in particular the chemical evolution in the young universe and what we may learn from the observations of the oldest stars. LÄS MER

7. 5. Stellar Ages for Galactic Archaeology : Methods and Applications

   Författare :Christian Sahlholdt; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy : formation; Stellar ages; Milky Way Galaxy; Low mass stars; Galaxy : disc; Galaxy : evolution; Fysicumarkivet A:2021:Sahlholdt;

   Sammanfattning : Galactic Archaeology is the study of the formation and evolution of the Milky Way through the properties of stars and stellar populations. The combination of stellar ages, chemical compositions, positions, and velocities can reveal the history of star formation and chemical enrichment in different regions of the Galaxy. LÄS MER