The gravitational instability of a non-uniformly rotating heat conducting medium in the presence of non-uniform magnetic field

Abstract

The paper investigates the effects of thermal conductivity and non-uniform magnetic field on the gravitational instability of a non-uniformly rotating infinitely extending axisymmetric cylinder in a homogeneous heat conducting medium. The non-uniform rotation and magnetic field are supposed to act along θ and z directions of the cylinder. It is found that the gravitational instability of this general problem is determined by the same criterion as obtained by Dhiman and Dadwal (Astrophys. Space Sci. 325(2):195-200, 2010) for the self-gravitating isothermal medium in the presence of non-uniform rotation and magnetic field with the only difference that adiabatic sound velocity is now replaced by the isothermal sound velocity. It is found that the thermal conductivity has stabilizing effect on the onset of gravitational instability. Further, the stabilizing/destabilizing effect of the non-uniform magnetic field on the gravitational instability of heat conducting medium has been discussed and is illustrated by considering some special forms of the basic magnetic fields.

Effect of rotation on the growth rate of magnetogravitational instability of a viscoelastic medium

“…Bondyopadhya [20] pointed out that the stellar interiors may get heated by the rotation of the system. Bel and Schatzman [21], Anand and Kushwaha [22] and Dhiman and Dadwal [23,24] studied the effects of non-uniform rotation and/or a non-uniform magnetic field on the onset of gravitational instability under varying assumptions.…”

On the Magnetogravitational Instability of a Ferromagnetic Dust Cloud in the Presence of Nonuniform Rotation

“…Bel and Schatzman [9] studied the effect of nonuniform rotation on the onset of gravitational instability and obtained a modified expression for the Jeans criterion, which is now known as the Bel and Schatzman criterion. Recently, Dhiman and Dadwal [10,11] also studied the simultaneous effect of nonuniform magnetic field and rotation on the gravitational instability of gaseous medium and obtained some general qualitative results.…”