منابع مشابه
Non-axisymmetric instability in thin discs
In a recent important paper, Papaloizou & Pringle (1984) have investigated the dynamical stability of a thick, differentially rotating disc of uniform entropy and uniform specific angular momentum. They find a strong global non-axisymmetric instability which grows on a dynamical time-scale. Here we show that a similar instability exists even in thin discs of arbitrary specific angular momentum....
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Context. The MHD instabilities can generate complex field topologies even if the initial field configuration is a very simple one. Aims. We consider the stability properties of magnetic configurations containing a toroidal and an axial field. In this paper, we concentrate mainly on the behavior of non-axisymmetric perturbations in axisymmetric magnetic configurations. Methods. The stability is ...
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We present a perturbation theory for studying the instabilities of non-axisymmetric gaseous discs. We perturb the dynamical equations of self-gravitating fluids in the vicinity of a non-axisymmetric equilibrium, and expand the perturbed physical quantities in terms of a complete basis set and a small non-axisymmetry parameter ǫ. We then derive a linear eigenvalue problem in matrix form, and det...
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Below a threshold energy, gas in the constant density core of a triaxial galaxy can find no simple non-intersecting periodic orbit to act as an attractor for its trajectory (El-Zant et al. 2003). If a disc of gas arriving from further out in the galaxy dissipates sufficient energy to fall below this threshold, it will thereafter collapse into the very centre. Such a mechanism may be relevant to...
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Purely gravitational perturbations are considered in a thin rotating disk composed of several gas and stellar components. The dispersion relation for the axisymmetric density waves propagating through the disk is found and the criterion for the local axisymmetric stability of the whole system is formulated. In the appropriate limit of two-component gas we confirm the findings of Jog & Solomon (...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1985
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/213.1.7p