Overview

• A diffuse radio glow wrapping PLCK G287.0+32.9 spans almost 20 million light-years, making it the largest halo of its kind ever observed.
• PLCK G287.0+32.9 lies about 5 billion light-years from Earth and is the product of an ongoing collision among three galaxy subclusters.
• Chandra’s X-ray images reveal box-shaped structures and a comet-like tail that align with MeerKAT’s radio features, indicating shockwaves and turbulence at work.
• The enormity of the halo challenges models of cosmic ray energization by showing electrons can emit across greater distances than previously thought.
• Uncertain funding for NASA’s Chandra X-ray Observatory puts future high-resolution studies of cluster dynamics and cosmic magnetic fields at risk.