Normally, astronomers would expect dense, hot gas like this to form stars, but they haven't found any evidence of stars here. Instead, they think, the black hole has prevented stars from forming by keeping the gas hot where it would normally cool, drop in pressure, and pull in more gas to form trillions of stars.

The black hole is so powerful, it's created gaps in the gas surrounding it. NASA explains:

The X-ray image shows two large cavities in the hot gas on either side of the central galaxy. The Chandra image has been specially processed to emphasize the cavities. Both cavities are aligned with jets seen in radio images from the VLA [Very Large Array]. The location of the supermassive black hole between the cavities is strong evidence that the supersonic jets generated by the black hole have drilled into the hot gas and pushed it aside, forming the cavities.

Astronomers have found other black holes that formed similar cavities, but these are unusually large—about the size of the Milky Way galaxy.

This and other evidence suggest the black hole could be "ultramassive," instead of merely supermassive, and have a mass more than 10 billion times that of the sun. It could also be extremely massive and spinning slowly.

A team of astronomers who studied the black hole published a paper about it in The Astrophysical Journal and on the paper server arXiv.