  The effect of radiative heat-loss function and finite ion Larmor radius (FLR)
corrections on the thermal instability of infinite homogeneous viscous plasma
has been investigated incorporating the effects of thermal conductivity and
finite electrical resistivity for the formation of a molecular cloud. The
general dispersion relation is derived using the normal mode analysis method
with the help of relevant linearized perturbation equations of the problem.
Furthermore the wave propagation along and perpendicular to the direction of
external magnetic field has been discussed. Stability of the medium is
discussed by applying Routh Hurwitzs criterion and it is found that thermal
instability criterion determines the stability of the medium. We find that the
presence of radiative heat-loss function and thermal conductivity modify the
fundamental criterion of thermal instability into radiatively driven thermal
instability criterion. In longitudinal direction FLR corrections, viscosity,
magnetic field and finite resistivity have no effect on thermal instability
criterion. The presence of radiative heat-loss function and thermal
conductivity modify the fundamental thermal instability criterion into
radiatively driven thermal instability criterion. Also the FLR corrections
modify the growth rate of the Alfven mode. For transverse wave propagation FLR
corrections, radiative heat-loss function, magnetic field and thermal
conductivity modify the thermal instability criterion. From the curves it is
clear that heat-loss function, FLR corrections and viscosity have stabilizing
effect, while finite resistivity has destabilizing effect on the thermal modes.
Our results show that the FLR corrections and radiative heat-loss functions
affect the evolution of interstellar molecular clouds and star formation.

Plasma Physics