Tirso Marin Gilabert - Viscous or Turbulent? The XRISM Puzzle of Coma
Please note this event occurred in the past.
September 23, 2026 12:00 pm - 1:00 pm ET
LGRT 533
The evolution of galaxy clusters is strongly shaped by the physics of the intracluster medium (ICM), where processes such as turbulence, mixing, and galaxy–ICM interactions drive much of the cluster's dynamical state. One key ingredient is viscosity, which can suppress small-scale gas motions and modify density fluctuations and magnetic fields. Yet, both the strength and nature of viscosity in the ICM remain uncertain.
In this talk, I will present results from high-resolution cosmological simulations that explicitly include viscosity, with a particular focus on the Coma cluster. Recent XRISM observations of Coma have revealed unexpectedly low small-scale gas motions, challenging our current understanding of ICM dynamics. I will explore whether viscosity can help explain these observations, comparing inviscid simulations with models including both isotropic and anisotropic viscosity. I will show how these different treatments affect cluster morphology, turbulence, and ICM fluctuations, and discuss how simulations and observations together can constrain the microphysics of the ICM.
In this talk, I will present results from high-resolution cosmological simulations that explicitly include viscosity, with a particular focus on the Coma cluster. Recent XRISM observations of Coma have revealed unexpectedly low small-scale gas motions, challenging our current understanding of ICM dynamics. I will explore whether viscosity can help explain these observations, comparing inviscid simulations with models including both isotropic and anisotropic viscosity. I will show how these different treatments affect cluster morphology, turbulence, and ICM fluctuations, and discuss how simulations and observations together can constrain the microphysics of the ICM.