The Impact of Magnetic Fields on Thermal Instability

Abstract

Multiphase gas structure is ubiquitous in our universe which exists in both galaxy clusters and galaxy halos. Recent results from COS (Cosmic Origins Spectrograph) suggest that large quantities of cold gas with temperature of a few 10^4 K are found in so called circumgalactic medium (CGM), which extends up to galactic virial radius (~ 100 kpc). However, the origin and stability of such cold gas still remains unclear. In this presented ongoing work, we explore thermal instability as a possible mechanism, and find that the existence of magnetic fields can significantly enhance thermal instability and modify the structure of multiphase gas (even for very weak fields), which is applicable for both ICM and CGM.