Variable streams self-gravitating instability of radiating rotating gas cloud

摘要

The self-gravitating instability of radiating rotating gas cloud (of density ρ0) streams with non-uniform velocity has been studied. The stability criterion of the model, for general wave propagation, is derived and the stability states are discussed. Jeans self-gravitating instability restriction has been obtained with some simplification here. The radiation effect stabilizes the gas cloud medium with critical wave length longer than that of Jeans. Normally, the streaming has a destabilizing effect. However, this effect is depressed in the presence of radiation. Neither the radiation nor the rotation stabilization influence affects the self-gravitating instability. So, the rotation and radiation do not prevent the destroying of the spiral arm of galaxy due to the influence of the self-gravitating force. However, if the wave propagation in xy-plane is normal to the direction of the rotation with angular speed Ω, the self-gravitating instability may disappear as long as Ω>(πGρ0)1/2, where G is the gravitational constant.