Evidence for two pairs of supermassive black holes in dwarf galaxies on collision courses has been found with Chandra. The two pairs are shown in X-rays from Chandra and optical light from the Canada-France-Hawaii telescope. The merger on the left is in a late stage and was given the single name of Mirabilis. The other merger is in the early stages and the two dwarf galaxies are named Elstir (bottom) and Vinteuil (top). Astronomers think that dwarf galaxies – those about 20 times less massive than the Milky Way – grow through mergers with others. This is an important process for galaxy growth in the early Universe and this discovery provides examples for scientists to study in greater detail.

This tactile plates is a composite image of galaxy collisions as a physical relief map based on the intensity of X-ray data captured by Chandra and optical data from other telescopes.

The plate features two colliding dwarf galaxies in the late stages of merging into one larger galaxy. In this plate, a cloud represents gas and stars in the merging galaxies. The shape at its core represents a black hole being tracked by the Chandra X-ray Observatory. Directly above the cloud is another black hole, followed by a tail, curving up and to our right, caused by tidal effects from the ongoing collision. Because these two dwarf galaxies are in the final stages of merging, scientists have given the combined galaxy a single name: Mirabilis.

This tactile plates is a composite image of galaxy collisions as a physical relief map based on the intensity of X-ray data captured by Chandra and optical data from other telescopes.

This plate features two colliding dwarf galaxies in the early stages of merging. In this pair of dwarf galaxies, a cloud with a raised circle at its core sits above a larger companion with a similar shape. These clouds are the dwarf galaxies known as Vinteuil and Elstir. The raised cores represent black holes tracked by Chandra. Elstir, the larger object, near the bottom, features wispy tendrils. Several of these tendrils appear to reach up toward the smaller galaxy, Vinteuil, creating a bridge of gas and stars.