The nature of low T/|W| dynamical instabilities in differentially rotating stars

A. L. Watts; N. Andersson; D. I. Jones

doi:10.1086/427653

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The nature of low T/|W| dynamical instabilities in differentially rotating stars

A. L. Watts·N. Andersson·D. I. Jones

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Abstract

Recent numerical simulations indicate the presence of dynamical instabilities of the f-mode in differentially rotating stars even at very low values of $T/|W|$, the ratio of kinetic to potential energy. In this Letter we argue that these may be shear instabilities which occur when the degree of differential rotation exceeds a critical value and the f-mode develops a corotation point associated with the presence of a continuous spectrum. Our explanation, which is supported by detailed studies of a simple shell model, offers a straightforward way of understanding all of the key features of these instabilities.

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A. L. Watts, N. Andersson, D. I. Jones. 2004-11-18. The nature of low T/|W| dynamical instabilities in differentially rotating stars. https://doi.org/10.1086/427653

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