Sökning: "Quasars"

Visar resultat 1 - 5 av 19 avhandlingar innehållade ordet Quasars.

  1. 1. Quasars and Low Surface Brightness Galaxies as Probes of Dark Matter

    Författare :Erik Zackrisson; Nils Bergvall; Kjell Olofsson; Julianne Dalcanton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Cosmology: dark matter; gravitational lensing; quasars: general; quasars: redshift; galaxies: halos; galaxies: formation; galaxies: stellar content; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

    Sammanfattning : Most of the matter in the Universe appears to be in some form which does not emit or absorb light. While evidence for the existence of this dark matter has accumulated over the last seventy years, its nature remains elusive. LÄS MER

  3. 2. Quasar host galaxies at intermediate and high redshifts

    Författare :Eva Örndahl; Bengt Gustafsson; Jari Kotilainen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Active galaxies; Quasars; Host galaxies; Imaging; Photometry; Magnitudes; Colours; Morphology; Statistical methods; High-redshift; Infrared; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : Quasars form one of the most energetic phenomena in the universe, and can be traced out to very large redshifts. By studying the galaxies which host the active nuclei, important insights can be gained into the processes that trigger and maintain the quasar powerhouse. LÄS MER

  4. 3. Extragalactic extinction and spectral properties of Type Ia supernovae

    Författare :Linda Östman; Ariel Goobar; Avishay Gal-Yam; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Type Ia supernovae; cosmology; spectroscopy; dust extinction; quasars; axions; Physics; Fysik; fysik; Physics;

    Sammanfattning : The use of Type Ia supernovae as standardisable candles for probing cosmological parameters with high precision requires good knowledge about how the supernova light is affected along the line of sight and how the intrinsic brightness varies between objects. The work in this thesis addresses these topics. LÄS MER

  5. 4. Numerical Studies of Extragalactic Objects. Analysis of mmVLBI Observations and Simulations of Barred Spiral Galaxies

    Författare :Mikael Lerner; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasars; galactic dynamics; barred galaxies; N-body simulations; VLBI; model fitting;

    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

  7. 5. Millimetre VLBI observations : hybrid mapping and model fitting

    Författare :Mikael Lerner; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VLBI; quasars; model fitting;

    Sammanfattning : .... LÄS MER