An Ultraluminous Collision

Two galaxies graze each other in this composite image that includes X-ray light (shown in pink) from NASA’s Chandra X-ray Observatory, optical light from the Hubble Space Telescope (in blue, white, orange, and brown), and infrared light (in red) from the Spitzer Space Telescope. As the galaxies collide, they’ve produced three supernovas in the last 15 years, along with one of the biggest collections astronomers have found — 28 so far — of “ultraluminous X-ray sources,” or ULXs.