Thermal Instability in Gravitationally-Stratified Plasmas: Implications for Multi-Phase Structure in Clusters and Galaxy Halos

Understand

We study the interplay among cooling, heating, conduction, and magnetic fields in gravitationally stratified plasmas using simplified, plane-parallel numerical simulations.

• Since the physical heating mechanism remains uncertain in massive halos such as groups or clusters, we adopt a simple, observationally-motivated prescription which enforces global thermal equilibrium when averaged over large scales.
• The plasma remains susceptible to local thermal instability, however, and cooling drives an inward flow of material.
• In contrast to previous results, we argue that the thermal stability of the plasma is independent of its convective stability.