Sökning: "N-body simulations"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden N-body simulations.
1. Stellar kinematics in surveys and simulations
Sammanfattning : We study stellar motions in the Milky Way with N-body simulations and large astrometric samples from ESA's Gaia mission. We identify two kinematic populations for white dwarfs in the Solar neighbourhood. We also investigate the accreted halo and reveal two new structures. LÄS MER
2. Numerical Studies of Extragalactic Objects. Analysis of mmVLBI Observations and Simulations of Barred Spiral Galaxies
Sammanfattning : Numerical studies related to high-frequency VLBI observations of quasars and dynamics of barred spiral galaxies have been performed. Data from a global 100 GHz VLBI experiment has been reduced and a radio image of the quasar 3C 446 with the highest resolution achieved to date has been produced. LÄS MER
3. The Dynamics of Star Cluster Formation
Sammanfattning : How do star clusters form? We care, since these are the birth sites of most stars, perhaps including our own Sun. There are a great variety of different theoretical models of cluster formation and our main goal in this thesis is to examine the implications of these for the dynamical evolution of a cluster's stellar population, including the ejected stars. LÄS MER
4. Radial Velocities Without Spectroscopy -Astrometric determination of stellar radial motion
Sammanfattning : This work demonstrates the determination of absolute stellar radial velocities from geometrical principles, i.e. using astrometry. Such `astrometric radial velocities' are obtained independently of spectroscopic information. LÄS MER
5. Cosmological Dark Matter and the Isotropic Gamma-Ray Background : Measurements and Upper Limits
Sammanfattning : This thesis addresses the isotropic diffuse gamma-ray background, as measured by the Fermi gamma ray space telescope, and its implications for indirect detection of dark matter. We describe the measurement of the isotropic background, including also an alternative analysis method besides the one published by the Fermi-LAT collaboration. LÄS MER