A kinetic model for rotating diluted gaseous envelopes in a central field

ROHRMANN, R. D.

Monthly Notices of the Royal Astronomical Society

John Wiley & Sons, Inc.

Año: 1997 vol. 285 p. 427 - 438

0035-8711

A model based on the kinetic theory is proposed for tenuous gaseous envelopes subject to a central attraction field. Quasi- steady states are studied where the gaseous system shows differential rotation. The particle density, the gas mean velocity and the kinetic temperature are analytically determined. The model predicts two possible configurations of gas distribution: normal envelope and shell, which can be defined in terms of relevant physical parameters, such as the intensity of the field and the angular velocity of the inner region of the system. The kinematic behaviour of the gas is analysed in detail by studying the hydrodynamic limit of the rotationally forced ejection of matter and the condition of escape. The importance of thermal wind in the external region of the envelope is considered.