Numerical Simulations of the Merging Cluster of Galaxies Cygnus A

The archetype FR-II galaxy Cygnus A lies in a moderately rich cluster of galaxies in which two subclusters are about to undergo a major merger. The active galactic nucleus (AGN) Cygnus A shows strong interactions with the cluster environment, a process called AGN feedback. The brightness and relative proximity of Cygnus A combined with the high spatial resolution of Chandra allows for a study of AGN feedback on Myr and kpc scales, but the observations comprise both AGN feedback and effects of the ongoing merger. The Cygnus cluster environment excluding the AGN is therefore studied using idealised binary merger simulations constrained by one megasecond of Chandra XVP observations of the hot intracluster medium. The total gravitating mass, dark matter halo properties and the baryon fraction are inferred from the observed density and temperature profiles under the assumption of hydrostatic equilibrium. This allows to set up numerical representations of both subclusters to simulate only the merger by means of smoothed particle hydrodynamics. The simulations provide the quiescent and merger-enhanced temperature structure of both subclusters. By examining the differences between the simulated and observed cluster we can ultimately study the effect of AGN feedback onto the (thermal structure of the) cluster. I will present my modelling work of the Cygnus cluster environment.

Timo Halbesma — API -- UvA
Thursday 9 March 2017, 12:00
Location: C4.174