Speaker
Description
Spiral structures and cold fronts in cool-core (CC) galaxy clusters are almost universally attributed to minor merger-induced gas sloshing. However, many CC clusters appear dynamically relaxed with no visible perturber, challenging this interpretation. Using three-dimensional cosmic-ray magnetohydrodynamic simulations of self-regulated AGN feedback in a Perseus-like cluster, we show that precessing, CR-dominated jets naturally produce spiral-like structures extending to ~150 kpc and accompanying cold fronts — driven by coherent fallback of jet-uplifted gas during AGN quiescent phases, without any external perturbation. Comparing kinematic signatures against XRISM/Resolve observations of Perseus, we find that while a merger simulation reproduces large-scale velocity gradients, it systematically underpredicts gas motions in the central ~30 kpc, where AGN-driven motions dominate. We further show that AGN quiescent phases produce a tangential bias in both velocity and magnetic fields, stabilising cold fronts against Kelvin–Helmholtz instabilities.
| Participate the oral/poster presentation award competition | No |
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