The Stability of Dilute Plasmas with Thermal and Composition Gradients. I. The Slow Conduction Limit: Overstable Gravity Modes

2011/11/14 by Martín E. Pessah, Martin E. Pessah, Sagar Chakraborty +2 · 1 citation
Physics and Astronomy · #Astrophysics and Star Formation Studies #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #astro-ph.CO

paper · pdf · doi:10.48550/arxiv.1111.3372

5 pages, 3 figures. Submitted to ApJ

arxiv created 2011/11/14 · openalex publication_date 2011/11/14 · arxiv updated 2011/11/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We analyze the stability of a dilute plasma with thermal and composition gradients in the limit where conduction is slow compared to the dynamical timescale. We find necessary and sufficient conditions for stability when the background magnetic field is either parallel or perpendicular to the thermal and composition gradients that are parallel to the gravitational field. We provide approximate solutions for all the relevant modes involved, which are driven by gravity, conduction, and diffusion. We discuss the astrophysical implications of our findings for a representative galaxy cluster where helium has sedimented.

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• THE STABILITY OF WEAKLY COLLISIONAL PLASMAS WITH THERMAL AND COMPOSITION GRADIENTS

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