Effect of ion radiative cooling on Jeans instability of partially ionized dusty plasma with dust charge fluctuation

摘要

In this paper, the effect of ion radiative cooling on the gravitational instability of dusty plasma is studied, incorporating dust charge fluctuation with dust-neutral, neutral-ion, and ion-neutral collisions. The basic equations are linearized using normal mode analysis to obtain a general dispersion relation. The general dispersion relation is analytically and numerically discussed to explain the role of ion radiative cooling in the structure formation through gravitational instability. The Jeans collapse criteria are found to be modified due to ion and electron radiative cooling, dust charge fluctuations, and collisions effects. It is determined from the analytical and numerical calculations that the support of radiative cooling of ions drives thermal fluctuations and gives instability to the system. The electron cooling effect remains dominating over ion cooling effect, and thus, it enhances the collapse more efficiently than ion cooling effect. Although the radiative cooling is slow, it may precede the collapse in molecular cloud, which further leads to the structure formation. The present work is relevance for the structure formation in the molecular cloud. Published by AIP Publishing.