Active galaxies give off bright radiation from their cores, where gas heats up as it is compressed into a swirling accretion disk encircling the black hole.
One of the most active star-forming regions near Earth, N11 is part of a complex network of gas clouds and star clusters in the Large Magellanic cloud, a neighboring galaxy.
The team chose 140 active galactic nuclei, or AGNs, by selecting galaxies that emit a lot of X-rays, which can Pierce the galactic gas and dust that might otherwise block the nuclei from view.