Sökning: "Radio interferometry"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden Radio interferometry.

  1. 1. Radio Studies of Circumnuclear Gas in Active Galaxies

    Författare :Ylva Pihlström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; techniques: interferometry; galaxies: starbust; galaxies: active; galaxies: nuclei; radio lines: galaxies; techniques: high angular resolution;

    Sammanfattning : In this thesis we have used radio interferometry in order to perform high resolution spectral line studies of circumnuclear gas in AGN and starburst galaxies. Amongst the studied objects is the Seyfert 2 NGC5793, for which we find the high opacity HI absorption to be consistent with a 50-100 pc radius atomic disk aligned with the host galaxy disk. LÄS MER

  3. 2. Mass Loss of Evolved Stars : Improving Mass-Loss Rates and Distances

    Författare :Miora Andriantsaralaza; Paul Barklem; Elvire De Beck; Susanne Höfner; Jacco van Loon; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AGB stars; Mass loss; Distance; Circumstellar matter; Radio interferometry; Stellar evolution; Fysik med inriktning mot astrofysik; Physics with specialization in Astrophysics;

    Sammanfattning : In the final stages of their lives, low to intermediate-mass stars enter the Asymptotic Giant Branch (AGB) phase, where they experience significant mass loss through dusty stellar winds. This mass loss is pivotal, not only for the chemical enrichment of the interstellar medium, setting the stage for new stars and planets to form, but also in dictating the evolution and the ultimate fate of the stars themselves. LÄS MER

  4. 3. Stacking of interferometric data at sub-millimeter and radio wavelengths

    Författare :Lukas Lindroos; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; techniques: interferometric; methods: data analysis; sub-millimetre: galaxies; galaxies: high- redshift; radio continuum: galaxies;

    Sammanfattning : Understanding the procceses of galaxy evolution require observational constraints on the physical properties of galaxies at different times in the history of the Universe. Large and deep surveys at visible and near-infrared wavelengths have, during the past decade, been used to produce extensive catalogues of high-redshift galaxies, spanning a large range of the history of the Universe. LÄS MER

  5. 4. High-resolution radio imaging of galaxy nuclei

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

    Sammanfattning : 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. LÄS MER

  7. 5. Observations of Artificial Radio Sources within the Framework of Geodetic Very Long Baseline Interferometry

    Författare :Grzegorz Klopotek; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; VGOS; Monte-Carlo simulations; geodetic VLBI; space geodesy; c5 ;

    Sammanfattning : Very long baseline interferometry (VLBI) is a mature and fascinating technique with unique and indisputable applications in radio astronomy, planetary sciences, and space geodesy. The latter discipline is a field of science facilitating our understanding of various global-scale phenomena connected to Earth dynamics. LÄS MER