Masomeh Arabikhah - Department of physics, Universtiy of Payame Noor, PO BOX 19395-3697 Tehran, IRAN
Sadollah Nasiri - Department of physics, University of shahid beheshti,Iran,

In this study, the effects of the equation of state on the star formation in turbulent molecular clouds have been investigated. The chosen flux was a self-gravitating and turbulent flux tube with a polytropic stratification, in which natural modes fluctuations were studied through varying polytropic parameter. Linear perturbations of flux were decomposed into irrotational and solenoidal component by using a gauged version of Helmholtz theorem. The irrotational components derived from a scalar potential, made up most parts of the pendulous modes of p, and the solenoidal component derived from a vector potential made up the pendulous modes of g.The specific frequencies of the functions were calculated using a Reyleigh-Ritz variational technique. The results show that the stable modes become unstable with increasing the polytropic parameter.

Galaxies, ISM, clouds, polytropic ,turbulence