The cross-talk between global dynamics in the ICM/CGM and microphysics (Prakriti Palchoudhury)

Diffuse, weakly collisional and weakly magnetised intracluster and circumgalactic media are not only crucial to understand the large scale galaxy formation physics across redshifts, but these are also ideal testbeds for exploring effects of plasma scale transport phenomena. The important X-ray observational probes include (not exhaustively) (i) Strong shock sites that can hint at Coulomb collisional timescale, (ii) weak/moderate compressible features and sharp contact discontinuity that can imply inefficient energy transport, (iii) incompressible density/temperature features can constrain survival timescale and length scales for thermal/buoyancy instabilities (thus also indirectly probing mixing of phases and transport physics), (iv) X-ray deficient bubble survival can constrain level of viscosity in the plasma. We find predictions on all these features from global MHD simulations at fractions of viral radius on one hand, and fully kinetic collisionless plasma simulations below the collisional mean free path on the other hand. Only observations can facilitate the understanding of cross-talk between the two scales which are orders of magnitude apart. All these investigations can be made possible by AXIS’s high spatial resolution and large effective area. In this talk, I will expand on a few of the examples mentioned above from the purview of theoretical/computational research.