Sökning: "accretion discs"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden accretion discs.

  1. 1. Formation and Evolution of Protoplanetary Discs

    Författare :Johan Appelgren; Astrofysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Protoplanetary discs; Accretion discs; planet formation;

    Sammanfattning : Protoplanetary discs and the protostars they surround are formed from the gravitational collapse of molecularcloud cores. These discs consist primarily of gas, with a small but important dust component. The roughlymm-sized grains that make up the dust component are the building blocks of planets. LÄS MER

  3. 2. Transport, Turbulence and Instabilities in Cosmic Magnetic Fields

    Författare :Giuseppe Di Bernardo; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cosmic Rays; Interstella Medium; Galactic Magnetic Fields; Magnetohydrodynamics Turbulence; Accretion Discs;

    Sammanfattning : This decade has seen a large number of space missions, which, alongside ground-based radio, optical and gamma-ray telescopes, have enabled a deep insight into the non-thermal astrophysical environments. Interstellar Medium (ISM), Supernovae Remnants (SNRs) and Black-Hole (BH) accretion discs (ADs) are only a few examples of natural habitat of interaction of relativistic particles and magnetic fields, largely mediated by the action of the turbulence. LÄS MER

  4. 3. Cooling the Envelopes of Gas Giants : Accretion, structure formation and observability

    Författare :Matthäus Schulik; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Planet formation; Hydrodynamics; Giant planets;

    Sammanfattning : We know now that discs of gas and dust, so-called protoplanetary discs, form planets as side-products of the naturally occurring star formation process throughout the Milky Way. Young, growing planets in such discs are commonly referred to as protoplanets. LÄS MER

  5. 4. Modelling and analyzing strong-field effects in quantum plasma

    Författare :Haidar Al-Naseri; Gert Brodin; Jens Zamanian; J. Tito Mendonca; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasma physics; Strong-field physics; Kinetic theory; Quantum plasma; fysik; Physics;

    Sammanfattning : Under the extreme conditions that can be found around dense stars and in the accretion discs of black holes, several strong-field quantum phenomena dominate the dynamics of the plasma. This includes the creation of matter and anti-matter from the vacuum (Schwinger mechanism), radiation reaction and Landau quantization. LÄS MER

  7. 5. Pre-Flight Development of the PoGOLite Pathfinder

    Författare :Mózsi Kiss; Mark Pearce; Gottfried Kanbach; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astroparticle physics; Astropartikelfysik;

    Sammanfattning : The Polarized Gamma-ray Observer (PoGOLite) is a balloon-borne instrument that will measure gamma-ray polarization in the energy range 25-80 keV from astronomical sources such as pulsars, accretion discs and jets from active galacticnuclei. The two additional parameters provided by such observations, polarizationangle and degree, will allow these objects to be studied in a new way, providing information about their emission mechanisms and geometries. LÄS MER