Dumbbell Galaxy

The binary supermassive black holes and their vast radio jets, seen in composite radio and X-ray light.

The Dumbbell Galaxy, also known as NGC 1128, is a member of the Abell 400 galaxy cluster with a peculiar dumbbell structure. This is because it actually comprises two galaxies in the process of merging. Both galaxies in the system harbor central supermassive black holes, which have become gravitationally locked into a binary system orbiting each other at a distance of 25,000 light years. The orbiting black holes shoot off gigantic microwave radio jets into the vast cloud of multi-million-degree X-ray emitting gas that pervades the cluster, creating a giant radio-emissions source known as 3C 75.

Computer simulations indicate that the binary supermassive black holes will gradually spiral in toward each other until they coalesce to form a single and even more massive black hole, sending gravitational waves across the universe and producing ripples in the fabric of space, which appear as minute changes in the distance between any two points.