Title : Multiphase turbulence simulations of the intracluster medium

Speaker : Rajsekhar Mohapatra (Australian National University)

Date & Time : 2022.07.25 (Mon) 2:00 PM

Location : Science Hall, B101

문의: 김태선 교수, tkimm@yonsei.ac.kr

Abstract

Jets driven by active galactic nuclei (AGNs), sloshing by passage of galaxies during infall and mergers can drive turbulence in the intracluster medium (ICM). Turbulence plays an important role in cluster thermodynamics through turbulent heating and turbulent mixing and can prevent runaway cooling in cool core clusters. However, current X-ray observations lack the spectral resolution to directly measure turbulent velocities in the hot ICM. The different indirect observational methods of measuring turbulence include X-ray brightness fluctuations, thermal Sunyaev Zeldovich effect (tSZ) fluctuations and velocity measurements of cold (~104 K) Halpha emitting filaments using integral field unit spectroscopy (IFU). Using our idealised simulations, we have studied the effects of the amount of turbulent heating and the method of driving (incompressible vs compressible) on different statistical properties of the ICM gas, such as its temperature and density distribution, velocities of hot (107 K gas) and cold (104 K) phases, etc. We use our results to constrain the different indirect observational techniques for measuring turbulent velocities, such as X-ray brightness fluctuations, thermal Sunyaev-Zeldovich effect fluctuations, which are dependent on the density and pressure fluctuations, respectively. We also correlate between the velocities of hot (107 K gas) and cold (104 K) phases which would let us recover hot phase velocities from IFU observations of the cold phase.

* Talk to be delivered in English