Diploma Thesis
Chemische Prozesse in primordialen Akkretionsscheiben
(Chemical Processes in Primordial Accretion Disks)
Alexandra Tachil
Abstract:
In the present diploma thesis a stationary accretion disc model is developed describing discs in the non-selfgravitating,
Keplerian selfgravitating as well as in the fully selfgravitating domain. Since the focus is set on modelling
population III accretion discs a primordial chemistry is investigated. For that purpose an analysis of the temporal
evolution of the chemistry in the primordial universe is performed. Moreover the chemical properties of such gases are
determined.
Employing a monopole approximation numerical solutions for selfgravitating regions of accretion discs are obtained which
do not depend on the radial structure of the disc itself. Based on this model protoplanetary as well as 'Milky-Way'-like
accretion discs are simulated. For a protoplanetary disc both the viscous and the chemical time scale are calculated. In
order to check whether or not the chemical equilibrium is achievable a comparison of both time scales is performed.
Thesis: ps.gz file (1942786 Bytes)
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