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Showing result 11 - 15 of 24 swedish dissertations matching the above criteria.

  2. 11. The environment of active galactic nuclei : excess counts and the nature of their host clusters

    Author : Margrethe Wold; Christopher D. Impey; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

    Abstract : This thesis presents observations of the galaxy environment of active galactic nuclei on galaxy cluster scales. In the first part, we quantify the galaxy environment of a sample of 40 quasars, consisting of equal fractions of radio-loud and radio-quiet sources. The sample covers a narrow range in redshift, 0.5 < z < 0. READ MORE

  4. 12. Active Galactic Nuclei in galaxy surveys : Empirical paths to the fiery hearts of cosmic beasts

    Author : Beatriz Villarroel; Andreas J. Korn; Takis Konstantopoulos; Moshe Elitzur; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomi;

    Abstract : Some galaxies emit excessive amounts of light from their centers, caused by accretion of gas onto super-massive black holes (SMBH). These galactic cores are often referred to as Active Galactic Nuclei (AGN) and they come in many different forms, distinguishable by their emission properties. READ MORE

  5. 13. Rearrangement of gas in disc galaxies

    Author : Núria Piñol Ferrer; Kambiz Fathi; Santiago Garcia-Burillo; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

    Abstract : Active galactic nuclei and bursts of star formation are two distinct phenomena that amply change their host environments. They are present in a significant number of galaxies at all redshifts. In this thesis, we aim toward a better understanding of the physical processes that allow for the formation and maintenance of these two phenomena. READ MORE

  6. 14. High-resolution radio imaging of galaxy nuclei

    Author : Eskil Varenius; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Arp220; star formation; NGC4418; M82;

    Abstract : Star formation and galaxy evolution are intimately linked together. A detailed understanding of the environment where stars form may help us explain the differences we see between galaxies today and at earlier times in the history of the Universe. READ MORE

  7. 15. Super Star Clusters in Blue Compact Galaxies : Evidence for a near-infrared flux excess and properties of the starburst phase

    Author : Angela Adamo; Göran Östlin; Erik Zackrisson; Richard de Grjis; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; starburst galaxy-extragalactic star clusters-dwarf merger; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; astronomi;

    Abstract : Luminous Blue compact galaxies (BCGs) are metal-poor actively star-forming systems, characterised by bright ultraviolet and blue luminosities. Hubble Space Telescope high-resolution data have revealed that the luminous star-forming knots in these galaxies are composed of hundreds of young massive star clusters. READ MORE