International Scholarly Research Network
ISRN Astronomy and Astrophysics
Volume 2012, Article ID 420938, 14 pages
doi:10.5402/2012/420938
Research Article
Effect of Radiative Heat-Loss Function and Finite Larmor Radius
Corrections on Jeans Instability of Viscous Thermally Conducting
Self-Gravitating Astrophysical Plasma
Sachin Kaothekar
1, 2
and R. K. Chhajlani
1
1
School of Studies in Physics, Vikram University, Madhya Pradesh, Ujjain 456010, India
2
Department of Physics, Mahakal Institute of Technology, Madhya Pradesh, Ujjain 456664, India
Correspondence should be addressed to Sachin Kaothekar, sackaothekar@gmail.com
Received 3 April 2012; Accepted 15 June 2012
Academic Editors: C. W. Engelbracht, A. Ferrari, F. Fraschetti, I. Goldman, and C. Meegan
Copyright © 2012 S. Kaothekar and R. K. Chhajlani. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
The effect of radiative heat-loss function and finite ion Larmor radius (FLR) corrections on the self-gravitational instability of
infinite homogeneous viscous plasma has been investigated incorporating the effects of thermal conductivity and finite electrical
resistivity for the formation of a star in astrophysical plasma. 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 Hurwitz’s criterion. We find that the presence of radiative heat-loss function and thermal conductivity modify the
fundamental Jeans criterion of gravitational instability into radiative instability criterion. From the curves we see that temperature
dependent heat-loss function, FLR corrections and viscosity have stabilizing effect, while density dependent heat-loss function
has destabilizing effect on the growth rate of self-gravitational instability. Our result shows that the FLR corrections and radiative
heat-loss functions affect the star formation.
1. Introduction
The problem of self-gravitational instability is widely investi-
gated due to its relevance to the fragmentation of interstellar
medium and its role in star formation. Also, the self-
gravitational instability of molecular clouds is connected to
the cloud collapse and star formation. Hayashi [1] has dis-
cussed the problem of evolution of protostars and discusses
the different phase of formation of protostar in connection
with variation of temperature and density. Shu et al. [2]
have investigated the problem of star formation in molecular
clouds and concluded that the star formation occurs mainly
in four phases. In this problem, the self-gravitational insta-
bility of dust and gas plays important role. Draine and Mckee
[3] have studied the theory of interstellar shocks. Mckee and
Ostriker [4] have discussed the theory of star formation.
They concluded that the key dynamical processes involved
in star formation are turbulence, magnetic fields, and self-
gravity. In this connection, the gravitational instability
of infinite homogeneous self-gravitating magnetized and
rotating plasma is also discussed by Chandrasekhar [5].
Several authors (Pacholczyk and Stodolkiewicz [6], Nayyar
[7], and Shaikh et al. [8]) have investigated the problem
of gravitational instability of plasma with different physical
parameters such as viscosity, finite electrical conductivity,
Hall current, thermal conductivity, magnetic field, and rota-
tion. Yang et al. [9] have investigated the problem of large-
scale gravitational instability and star formation. Borah and
Sen [10] have investigated the gravitational instability of
partially ionized molecular clouds considering the effects of
electrons, ions, and charged dust grains. Avinash et al. [11]
have studied the dynamics of self-gravitating dust clouds
and the formation of planetesimals. Thus we find that a
large number of problems are discussed for self-gravitating
dusty and nondusty plasma with different parameters under
various assumptions due to its importance in star formation
and in many astrophysical situations.