Onset of turbulent re-acceleration in clusters

Ascertain whether the onset of turbulent re-acceleration of cosmic-ray electrons in galaxy clusters occurs at specific times associated with minor and major mergers and accretion flows, or instead through multiple onsets.

Background

The paper evaluates super-Alfvénic turbulent re-acceleration by comparing acceleration and cooling times across the merger evolution and finds intervals where re-acceleration could be efficient over significant volumes.

However, the timing and triggering of re-acceleration episodes—whether tied to particular merger stages or arising in multiple phases—remain unresolved, limiting predictive modeling of diffuse radio halo and mega-halo phenomenology.