English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Over the last decade, substantial efforts have been devoted to understandingthe stability properties, transport phenomena, and long-term evolution ofweakly-collisional, magnetized plasmas which are stratified in temperature.These studies have improved our understanding of the physics governing theintra-cluster medium (ICM), but assumed that ICM is a homogeneous. This,however, might not be a good approximation if heavy elements sediment in theinner region of the galaxy cluster. In this paper, we analyze the stability ofa weakly-collisional, magnetized plane-parallel atmosphere which is stratifiedin both temperature and composition. This allows us to discuss for the firsttime the dynamics of weakly-collisional environments where heat conduction,momentum transport, and ion-diffusion are anisotropic with respect to thedirection of the magnetic field. We show that, depending on the relative signsand magnitudes of the gradients in the temperature and the mean molecularweight, the plasma can be subject to a wide variety of unstable modes whichinclude modifications to the magnetothermal instability (MTI), theheat-flux-driven buoyancy instability (HBI), and overstable gravity modespreviously studied in homogeneous media. We discuss the astrophysicalimplications of our findings for a representative galaxy cluster where heliumhas sedimented. Our findings suggest that the core insulation that results fromthe magnetic field configurations that arise as a natural consequence of theHBI, which would be MTI stable in a homogeneous medium, could be alleviated ifthe mean molecular weight gradient is steep enough, i.e., $(\nabla \mu)/\mu >(\nabla T)/T$. This study constitutes a first step toward understanding theinteraction between magnetic turbulence and the diffusion of heavy elements inthe ICM. (abridged)

The Stability of Weakly Collisional Plasmas with Thermal and Composition Gradients