The black hole in the binary system V4641 Sagittarii behaves like a giant blender. It sucks in matter from its companion star and flings it back into space in two narrow jets. These jets slam into the surrounding gas like a water jet hitting sand, gradually carving out a huge cavity around the hole.
The MeerKAT radio telescope in South Africa observed this system for several hours. The images revealed a bow-tie-shaped cloud — two elongated loops extending from the hole in opposite directions. The cloud spans 35 light-years. That's like stretching a glowing thread from the Sun to the nearest star, then pulling it ten times longer.
What accelerates particles to such energies? Most likely, shock waves within the jets. When a fast flow plows into slower gas, it piles it up ahead like a bulldozer. At this front, particles bounce back and forth across the boundary, gaining speed. This is how electrons in the cloud get accelerated to energies thousands of times beyond what the Large Hadron Collider can achieve.
The cloud around V4641 Sagittarii is a rare find. It shows that even small black holes can 'blow' into space for decades, creating structures as large as entire star clusters. Perhaps such clouds once helped cosmic rays fill our Galaxy.
The MeerKAT radio telescope consists of 64 antennas, each the size of a three-story building. Together, they capture radio waves as sharply as a single giant eye 8 kilometers in diameter.