A new study using NASA’s Chandra X-ray Observatory has tracked two pairs of supermassive black holes in dwarf galaxies on collision courses. This is the first indication of such an upcoming encounter, giving scientists crucial knowledge about the growth of black holes in the early Universe.

It is well known that dwarf galaxies merge to grow into the larger galaxies seen today. However, current technology cannot observe the first generation of dwarf galaxy mergers because they are extraordinarily faint at great distances.

The current study overcame these hurdles by employing a systematic scan of deep Chandra X-ray observations and combining them with optical data from the Canada-France-Hawaii Telescope and infrared data from NASA’s Wide Infrared Survey Explorer (WISE) (CFHT).

The team searched for pairs of bright X-ray sources in colliding dwarf galaxies as evidence of two black holes and discovered two examples.

The composite image on the left shows one pair in the galaxy cluster Abell 133, 760 million light-years away from Earth. Pink represents Chandra X-ray data, while blue represents CFHT optical data. This pair of dwarf galaxies exhibit a long tail from tidal effects from the collision and seems to be in the last stages of merging.