On the Helium fingers in the intracluster medium

Shubhadeep Sadhukhan, Himanshu Gupta, Sagar Chakraborty

Published 2017-02-06Version 1

The primary goal of this paper is to build upon the machinery usually employed to study the salt finger instability in order to address the onset of the similar double diffusive convection phenomenon in the intracluster medium --- the weakly-collisional magnetized inhomogeneous plasma permeating galaxy clusters; and subsequently, to investigate the nature of the width of the analogous Helium fingers in the supercritical regime of the instability. Specifically, we conclude that the width of the Helium fingers scales as one-fourth power of the radius of the inner region of the ICM. In the process, we also find out the explicit mathematical expression of the criterion for the onset of the heat-flux-driven buoyancy instability modified by the presence of inhomogeneously distributed Helium ions in the galaxy cluster. This criterion incorporates the contribution of the magnetic tension into it.