Arp 147 is a straight-up galactic collective. It is composed of two galaxies that collided way back in the past, the results of which have set off a ring of awesome.
[The galaxies collided in the past which triggered] a wave of star formation (blue ring in galaxy at right). A number of these stars exploded as supernovae, producing black holes. Some of these, thought to weigh 10 to 20 times as much as the sun, shine brightly in X-rays (pink blobs) as they rob matter from companion stars.
Arp 147 is currently the dopest one-two galactic punch in the universe. That I know about.
