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arXiv · 2606.25730

The SKA View of Cool-core Clusters: Evolution of Radio Mini-halos and AGN Feedback

Myriam Gitti·Paolo Tozzi·Francesco Ubertosi·Annalisa Bonafede·Gianfranco Brunetti·Rossella Cassano·Stefano Ettori·Luigina Feretti·Marie-Lou Gendron-Marsolais·Simona Giacintucci·Julie Hlavacek-Larrondo·Alessandro Ignesti·Giulia Macario·Mamta Pandey-Pommier·Tiziana Venturi
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Abstract

In about 70 per cent of relaxed, cool-core galaxy clusters, the brightest cluster galaxy (BCG) is radio loud, showing non-thermal radio jets and lobes ejected by the central active galactic nucleus (AGN). In recent years such relativistic plasma has been shown to interact with the surrounding thermal intra-cluster medium (ICM) as revealed by striking images where radio lobe fill the cavities in the X-ray-emitting gas. This "radio-mode feedback" phenomenon is widespread and crucial for understanding the physics of cluster cores and the properties of the central BCG. Mechanically-powerful AGN are expected to drive turbulence in the central ICM which may also contribute to the origin of non-thermal emission on cluster-scales. Diffuse non-thermal emission has been observed in many cool-core clusters in the form of a radio mini-halo surrounding the radio-loud BCG on scales comparable to the cooling radius. Large samples of mini-halos are essential to clarify their origin and their link with the thermal and dynamical properties of clusters, especially in view of future high-resolution X-ray studies with NewAthena X-IFU. All-sky surveys with the SKA-Mid telescope at arcsecond resolution would have the potential to detect up to about 3500 mini-halos at redshift z<1 (compared to the few tens currently known). Deep Tier surveys with the SKA-Mid at sub-arcsecond resolution would further enable a complete census of radio-loud BCGs down to 1.4 GHz powers of 10^23 W/Hz up to z~2. This will provide a comprehensive view of AGN feedback and its role in shaping large scale structures.

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Myriam Gitti, Paolo Tozzi, Francesco Ubertosi, Annalisa Bonafede, Gianfranco Brunetti, Rossella Cassano, Stefano Ettori, Luigina Feretti, Marie-Lou Gendron-Marsolais, Simona Giacintucci, Julie Hlavacek-Larrondo, Alessandro Ignesti, Giulia Macario, Mamta Pandey-Pommier, Tiziana Venturi. 2026-06-24. The SKA View of Cool-core Clusters: Evolution of Radio Mini-halos and AGN Feedback. https://arxiv.org/abs/2606.25730

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