Thermal Conduction and Multiphase Gas in Cluster Cores
  We examine the role of thermal conduction and magnetic fields in cores of
galaxy clusters through global simulations of the intracluster medium (ICM). In
particular, we study the influence of thermal conduction, both isotropic and
anisotropic, on the condensation of multiphase gas in cluster cores. Previous
hydrodynamic simulations have shown that cold gas condenses out of the hot ICM
in thermal balance only when the ratio of the cooling time ($t_{\rm cool}$) and
the free-fall time ($t_{\rm ff}$) is less than $\approx 10$. Since thermal
conduction is significant in the ICM and it suppresses local cooling at small
scales, it is imperative to include thermal conduction in such studies. We find
that anisotropic (along local magnetic field lines) thermal conduction does not
influence the condensation criterion for a general magnetic geometry, even if
thermal conductivity is large. However, with isotropic thermal conduction cold
gas condenses only if conduction is suppressed (by a factor $\lesssim 0.3$)
with respect to the Spitzer value.
