Sökning: "Galaxy: globular clusters"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Galaxy: globular clusters.

  1. 1. The nature of stars with a common origin: clues from metallicity, elemental abundances, and kinematics

    Författare :Cheng Liu; Astronomi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Stars: abundances; Galaxy: evolution; Galaxy: solar neighbourhood; Galaxy: bulge; Galaxy: globular clusters;

    Sammanfattning : Most of field stars originate from dissolved star clusters. If the gas cloud is well mixed the stars in the cluster are expected to be chemically homogenous. LÄS MER

  2. 2. Exploring the Chemical Evolution of Globular Clusters and their Stars : Observational Constraints on Atomic Diffusion and Cluster Pollution in NGC 6752 and M4

    Författare :Pieter Gruyters; Andreas Korn; Piercarlo Bonifacio; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; stars: abundances – stars: atmospheres – stars: fundamental parameters – globular clusters: individual: NGC 6752 and M4 – techniques: spectroscopic; Astronomy with specialization in Astrophysics; Astronomi med intiktning mot astrofysik;

    Sammanfattning : Through the cosmic matter cycle, the chemical evolution of the Milky Way is imprinted in the elemental abundance patterns of late-type stars (spectral types F to K). Due to their long lifetimes ( 1 Hubble time), these stars are of particular importance when it comes to studying the build-up of elements during the early times of our Galaxy. LÄS MER

  3. 3. Young Stellar Clumps and Clusters in the Local Universe

    Författare :Matteo Messa; Göran Östlin; Angela Adamo; Petri Väisänen; Stockholms universitet; []

    Sammanfattning : The thesis introduces the process of star formation at the scale of galaxies, where a turbulent--dominated interstellar medium (ISM) can locally collapse under self-gravity. This collapse results in a star formation process which is hierarchical both in space and time. LÄS MER

  4. 4. On the origin and evolution of blue compact galaxies

    Författare :Göran A. Östlin; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galaxies - compact; formation; evolution; starburst; interactions; dwarf; photometry; kinematics and dynamics; low surface brightness galaxies; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

    Sammanfattning : This thesis is focused on the origin and evolution of blue compact galaxies (BCGs). BCGs are low mass galaxies characterised by blue colours, low chemical abundances and high star formation rates. The gas consumtion time scale is considerable shorter than the age of the universe and thus the high star formation rate must be transient. LÄS MER

  5. 5. On the Einstein-Vlasov system: Stationary Solutions and Small Data Solutions with Charged and Massless Particles

    Författare :Maximilian Thaller; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; non-linear wave equation; symmetric hyperbolic system; massless Einstein-Vlasov system; Minkowski stability; Einstein-Vlasov-Maxwell system; Vector Field Method; Conformal Einstein Field Equations; Static Solutions; General Relativity; Vlasov matter;

    Sammanfattning : The Vlasov matter model describes an ensemble of collisionless particles moving through space-time. These particles interact via the gravitational field which they create collectively. In the framework of General Relativity this gravitational field is described by space-time curvature. LÄS MER